Unisa Study Notes



PYC3703 – Cognitive Psychology -

Dialectic – a developmental process whereby an idea evolves over time:

Thesis – a statement of believe

Antithesis – a statement that counters a previous statement

← Debate between thesis and antithesis leads to a synthesis of both views (nature + nurture debate)

Philosophy – Seeks to understand general nature, in part through introspection

Physiology – Scientific study of life-sustaining functions, primarily through empirical methods (observation based)

Rationalist – the route to knowledge is through logical analysis and reason contemplation / introspection

Empiricist – We acquire knowledge via empirical evidence, through experience and observation

1. Rene Descartes – Rationalist

2. John Locke – Empiricist – “Tabula Rosa” – blank slate – life and experiences write knowledge on us, we have no innate ideas

3. Immanuel Kant – dialectically synthesised the views of Descartes and Locke

STRUCTURALISM

Understand the structure of the mind and it’s perceptions by analysing the perceptions into their constituent components

Perception of a flower: colour, geometric forms, size

The method of structuralism = introspection

The focus of structuralism = elementary structures of sensation

FUNCTIONALISM

Focus is on the process of thought, not the contents

The how and why

PRAGMATISM

Knowledge is validated by its usefulness, what you can do with it

ASSOCIATIONISM

• Examines how events / ideas become associated with one another in the mind to result in learning

• Contiguity = associating things that tend to occur together at the same time

• Herman Ebbinghaus – Associationist – studied own mental processes

• Counted his errors and recorded response times

• Studied how people learnt through rehearsal

• Edward Lee Thorndike – role of satisfaction key to forming associations

• “LAW OF EFFECT” – Stimulus will produce certain response over time, if organism is rewarded for that response. Satisfaction serves as stimulus for further actions

BEHAVIOURISM – extreme form of associationism

← Relation between observable behaviour and environmental stimuli. Focus on overt observable behaviour

← Pavlov – Classic conditioning learning – dog + bell + saliva – dog had no control

← Effective conditioning requires contingency – presentation of food contingent on presentation of conditioned stimulus

← Radical behaviourist - John Watson & BF Skinner

← Skinner – believed in OPERANT CONDITIONING – behaviour contingent on absence / reinforcement of reward or punishment – this explains all behaviour

GESTALT PSYCHOLOGY – critic of behaviourism

← We cannot fully understand behaviour by breaking down phenomena into smaller parts – we must view them as organised, structured wholes

← Gestalts – study insights – try to understand unobservable mental events

← “The whole differs from the sum of its parts” – the perception of a flower needs the whole experience, not just description of colour, form, size.

ASSUMPTION

← A statement / fact whose truth is presupposed

← When studying the mind / cognition – need to make assumptions about how the mind works and need a starting point

← Freud – mind was conceptualised as a steam engine / hydraulic system with pressure relief valves

← Cognitive psychology – assumption of mind as a computer / info. Processing system

← Cognitive system has a level of software (mind) and hardware (brain)

← PDP APPROACH – Parallel Distributed Processing Networks / The connectionist / neural network – the key to knowledge representation lies in the connections among various nodes

Cognitive Psychologists – approach based on 2 assumptions

1. The mind can be conceptualised as an information processing system

2. Internal mental activities exist and can be studied systematically using scientific approach. A methodological assumption based on idea that

- Experimental procedures

- Computer simulation can be used to study the mind scientifically

- Mathematical modelling

- Modern technological instruments

PLATO’S THEORY OF FORMS

Aristotle - Empiricist – knowledge depends on experience

Plato – Rationalist - Knowledge and truth should be investigated by reasoning and logical deduction. The true nature of reality does not reside in observable phenomena, but in abstract forms that underlie the phenomena.

← What we perceive = shadows

← The concept of ‘beauty’ provides a standard against which objects can be judged.

← The standard AKA the FORM / IDEAL

← Plato’s assumption – the meaning of a concept resides in the abstract form.

← The actual example only points to the ideal, they ‘stand in’ for it

← True forms are only imperfect reflections

COGNITIVISM – a synthesis of behaviourism (focus on observable) and gestaltism (internal mental processes)

A belief that much of human behaviour can be understood in terms of how people think

George Miller – the magic number 7

- People can remember 7 bits of info.

- Channel capacity – the upper limit with which an observer can match a response to info given – remembering 7 number sequentially – channel capacity = 7. Short term memory

Jerry Fodor – concept of modularity of mind

← Mind has distinct modules to deal with linguistics and info.

← Processes used in one domain operate independently of processes in other domains.

PHRENOLOGY – Measurement of human skull

Mental cartography (maps) gave rise to idea of modularity.

GOALS OF RESEARCH

1. DATA GATHERING

2. STATISTICAL MEANS OF ANALYSING THE DATA - allow a formation of a description of the phenomena . To move beyond description – leap from observation to inference (explain)

3. START WITH A THEORY – an organised body of general explanatory principles regarding a phenomena – based on observation

4. A HYPOTHESIS IS GENERATED - a tentative proposal regarding expected empirical consequences of theory

5. HYPOTHESIS TESTED THROUGH EXPERIMENTATION and findings subjected to statistical analysis to determine their statistical significance

RESEARCH METHODS

1. CONTROLLED LABORATORY EXPERIMENTS

2. PSYCHOBIOLOGY RESEARCH

3. SELF-REPORTS

4. CASE STUDIES

5. NATURALISTIC OBSERVATIONS

6. COMPUTER SIMULATIONS (pc to simulate / imitate human cognitive performance) AND AI (PC to demonstrate intelligent cognitive performance, brute force, does not represent how humans functions, but plays at highest possible level)

EXPERIMENTS ON HUMAN BEHAVIOUR

Lab setting – 2 variables

INDEPENDENT VARIABLE – individually manipulated while other aspects are held constant (Treatment)

DEPENDENT VARIABLE – outcome responses, values depend on how independent variable influences participants

Manipulate independent variable to observe effect on dependent variable

CONTROL VARIABLE - controls for effects of irrelevant variables which are held constant

CONFOUNDING VARIABLE - Irrelevant variables left uncontrolled which can influence results (time of day)

- Sample used must be representative and random – from population of interest

- Rigorous control over experimental conditions necessary

- Participants randomly assigned to treatment and control – allowing inference to be made of the effects of the independent variable (treatment) on the dependent variable (outcome)

Psychologists who study cognitive processes with reaction time use – SUBTRACTION METHOD

← Estimating the time a cognitive process takes by subtracting the amount of time information processing takes with the process, from the time without the process

← If outcomes in the treatment condition show statistically significant difference from outcomes in the control – one can infer a causal link between independent and dependent variables.

Independent variable involve

← Characteristics of the situation (presence vs. absence of stimuli)

← Characteristics of the task ( reading vs. listening)

← Characteristics of the participants (age diff, education) – not easily manipulated

CORRELATION – A statistical relationship between 2 or more attributes – expressed through a correlation coefficient called PEARSON’S R

PEARSON’S R = -1.00 (negative correlation) to +1.00

It describes the strength of a relationship. The closer to +1 –the stronger the relationship between the variables

A POSITIVE RELATIONSHIP – as one variable increases (vocab size) another variable increases (reading)

A NEGATIVE RELATIONSHIP – one variable increases (fatigue) another variable decreases (alertness)

If the correlation coefficient = 0 then there is no relationship between the variables.

PSYCHOBIOLOGICAL RESEARCH - relationship between cognitive performance and cerebral events and structures

← 3 techniques

1. POSTMORTEM

2. STUDYING IMAGES showing structures of / activities in the brain of individual known to have cognitive defect

3. OBTAINING INFO. ABOUT CEREBRAL PROCESSES during normal performance of cognitive activity

- IN VIVO – while alive – studies of individuals with known defects

- Studying cerebral activity in animals – mapping neural activity

UNDERLYING THEMES IN THE STUDY OF COGNITIVE PSYCHOLOGY

NATURE VS. NURTURE

Thesis / Antithesis: which is more influential in human cognition, human characteristics (nature) or environment (nurture)

Synthesis: How an impoverished environment adversely affects someone whose genes otherwise might have led to success

RATIONALISM VS. EMPIRICISM

Thesis/Antithesis: How do we discover truth about ourselves / world, logical reasoning (rationalism) or observing and testing (empiricism)

Synthesis: How can we combine empirical methods to learn the most we can about cognitive processes

STRUCTURES VS. PROCESSES

Thesis / Antithesis: contents, attributes, products of the mind or processes of thinking?

Synthesis: How do mental processes operate on mental structures

DOMAIN GENERALITY VS. DOMAIN SPECIFICITY

Thesis / Antithesis: Are processes limited to a single domain or generally across a variety of domains. Do observations in one domain apply to all, or only the specific domain in which they are observed

Synthesis: Which processes are domain general and which are domain specific

VALIDITY OF CAUSAL INFERENCES VS. ECOLOGICAL VALIDITY (the degree to which particular findings in one environmental context may be considered relevant outside the context)

Thesis / Antithesis: Study cognition using highly controlled experiments that increase probability of valid inferences of causality or use naturalistic techniques which increase the likelihood of getting ecologically valid findings

Synthesis: How can a variety of methods be combined (lab + naturalistic) that converge on findings that hold up

APPLIED VS. BASIC RESEARCH

Thesis / Antithesis: Research into fundamental cognitive processes or study ways in which to help people use cognition effectively

Synthesis: Combine the 2 dialectically so that basic leads to applied which lead to basic

BIOLOGICAL VS BEHAVIORAL

Thesis / Antithesis: Study the brain while its functioning or study people’s behaviour in cognitive tasks?

Synthesis: How to synthesis the methods so that we understand cognitive phenomena at multiple levels of analysis

Key ideas in CP

Data can only be fully understood in the context of an explanatory theory

1. Theories give meaning to data

A theory without data is empty

Theory assists in explanation (how) and prediction

Science requires empirical testing of theories – failing which they remain speculation

2. Cognition is generally adaptive, but not in all specific instances

Cognition systems allow us to learn, reason, remember, perceive with accuracy – despite barrage of environmental stimuli

Memories and reasoning processes are susceptible to systematic errors

3. Cognitive processes interact with each other and with other non-cognitive processes

Memory processes depend on perceptual processes – thinking depends on memory

Learning that causes changes in the brain can affect biological structures, just as biological structures can affect cognitive processes

4. Cognition needs to be studied through a variety of scientific methods

No best method

Varied methods seek a common understanding

The more diff. techniques that lead to same conclusion, the higher confidence we can have in the conclusion

5. All basic research in CP may lead to applications

All applied research (immediate application) may lead to basic understandings

Basic finding – learning is superior when spaced over time. This basic finding has an immediate application to study strategies

NEUROTRANSMITTERS

|Neurotransmitter |Description |Function |Specific examples |

|ACETYLCHOLINE (Ach) |Monoamine synthesized from Choline|Excitatory in brain |Involved in memory due to high concentration found in |

| | |Excitatory at skeletal muscles |hippocampus |

| | |Inhibitory at heart muscles |Role in sleep and arousal |

|DOPAMINE (DA) |Monoamine synthesized from |Influences movement, attention & learning |Parkinson’s – tremors and limb rigidity from too little |

| |Tyrosine |Mostly inhibitory |DA |

| | |Some excitatory |Associated with attention and learning & motivational |

| | | |processes – reward and punishment |

| | | |Schizophrenia – High level of DA |

|EPINEPHRINE & NOREPINEPHRINE|Monoamine synthesized from |Hormones – adrenaline and noradrenaline |Fight / flight / anger or fear |

| |Tyrosine |involved in alertness | |

|SEROTONIN |Monoamine synthesized from |Inhibitory to arousal, sleep, mood, |Defects in serotonin linked to depression |

| |Tyrosine |dreaming |Role in eating behaviour and body weight regulation |

| | | |High serotonin levels – anorexia |

| | | |Involved in aggression – drugs that block serotonin |

| | | |result in aggressive behaviour |

| | | |Inhibits dreaming |

|GABBA – Gamma Amniobutyric |Amino acid neurotransmitter |Inhibitory influence on presynaptic axons|Influences certain mechanisms for learning and memory |

|acid | | | |

|GLUTAMATE |Amino acid |Excitatory influence on presynaptic axons | |

|NEUROPEPTIDES |Peptide chains serving as |Influence on postsynaptic membrane |Endorphins – pain relief, neuromodulating neuropeptides |

| |neurotransmitters | |released to enhance effects of Ach |

ACUTE TOXICITY

Damage from a particular overdose, treated with Naloxone – which blocks the effects of narcotics by occupying opiate receptors in the brain. Not addictive but short lived.

CHRONIC TOXICITY

Damage done from long term addiction

In narcotic detoxification, methadone is substituted for narcotic (heroin) – binds to receptor sites and reduces cravings (but is addictive)

Electrical recordings of the brain

EEG – ELECTROENCEPHALOGRAM

← Recordings of electrical activity of the brain – which appears as waves of diff. width (frequency) and height (intensity)

← Event-Related-Potential (ERP) = the record of a small change in the brains electrical activity in response to stimulation. Reveals general information about location of activity

Static Imaging techniques

MRI – MAGNETIC RESONANCE IMAGING

← Strong magnetic field passes through brain

← Scanner detects various patters of electromagnetic changes in the atoms – which produce 3D image

← Musicians who play string instruments – expansion of brain in R hemisphere, which controls L hand movement. Shows how experience affects the brain development

CT – Computer Tomography x-ray based allow for observations of large abnormalities

Angiogram

METABOLIC IMAGING

← Rely on changes taking place in the brain after consumption of glucose and oxygen

← An area specifically required by one task should show more activity during the task

← Subtraction method: Subtracting activity during a general task from an activity during task of interest – analysis determines which areas are responsible for performance of particular task.

PET – POSITRON EMISSON TOMOGRAPHY SCAN

← Participant given (radioactive) oxygen that emits positrons as it’s metabolised

← PET scan measures increase in oxygen consumption in active brain areas during particular kinds of info processing

← Brain scanned to detect positrons

← Not highly precise – 30sec delay to produce data

FMRI – FUNCTIONAL MAGNETIC RESONANCE IMAGING

← Uses magnetic fields that induces changes in the particles of oxygen atoms

← Participant performs a task while in MRI machine

← More active areas of the brain draw more oxygenated blood

← The diff. in the amount of oxygen consumed form basis for FMRI measurement.

← Less invasive than PET – no radioactive particles used

← Expensive and time consuming

PHMRI – PHARMACOLOGICAL MRI

← Combines FMRI with study of psychopharmacological agents

← Study of influence and role of particular psychopharmacological agents on the brain

← Allowed examination of AGONISTS – strengthen responses & ANTAGONISTS – weaken responses – on same receptor cells

← Used for examination of drugs for treatments

DTI - DIFFUSION TENSOR IMAGING

← Examines the restricted dispersion of water in tissue

← Useful in mapping white matter and neural circuits

New / Recent techniques:

TMS – TRANSCRANIAL MAGNETIC STIMULATION

← Temporarily disrupts normal activity of the brain in a limited area

← Passing electrical current through persons head – which generate magnetic field, which disrupts an area

MEG – MAGNETOENCEPHALOGRAPHY

← Measures activity of the brain from outside the head by picking up magnetic fields emitted by changes in brain activity

← Allows localisation of brain signals

← Most precise measuring method – can locate pathological structures

The blood brain barrier

Cells that form the walls of the capillaries in the brain press together to block many substances from entering the brain, while allowing others to pass

2 categories of molecules that easily cross the blood brain barrier

i. Small uncharged molecules - oxygen, carbon dioxide

ii. Molecules that dissolve in the fats of the capillary walls (psychiatric drugs, heroine, nicotine)

2 proteins – 2oncilin and 2OT – interact with receptors in the brain to selectively open the barrier at certain sites to allow beneficial chemicals to enter – glucose, amino acids, hormones, certain vitamins

COGNITION IN THE BRAIN

FOREBRAIN – (CBLTH) MOST RECENT EVOLUTION OF THE BRAIN & LAST PORTION TO DEVELOP PRENATALLY

Position – top and front

Thinking and mental processes

Comprises of:

- CEREBRAL CORTEX: enables us to think – makes us human

- BASAL GANGLIA: Neurons critical to motor function

Dysfunction = tremors, involuntary movements – Parkinson’s & Huntington’s

- LIMBIC SYSTEM (ASH): Emotion, motivation, memory, learning

← Animals operate on instinct – have an underdeveloped limbic system

← Humans – more developed, allowing us to suppress instinctive response (hit someone)

← Allows us to adapt our behaviour in a changing environment

← Comprises 3 central interconnected cerebral structures

a) AMYGDALA - emotion – anger – aggression

← Stimulation results in fear (heart palpitations / flashbacks)

← Damage to amygdala – maladaptive lack of fear

← Amygdala has an enhancing effect for perception of emotional stimulus

← Autism – limited activation in amygdala

← Lesions in amygdala result in visual agnosia (can’t recognise objects) and hyper-sexuality

b) SEPTUM – Anger and fear

c) HIPPOCAMPUS – memory formulation

← Damage / removal – unable to form new memories, new info. Remains forever new

← Keeps track of where things are and spatial location to each other

← Korsakoff’s syndrome produces loss of memory function believed to be associated with damage to hippocampus - Can result from excessive alcohol use

← Disruption in hippocampus – deficits in declarative memory (2 + 2 = 4) but no in procedural memory (drive a car)

- THALAMUS: Relays incoming sensory info through groups of neurons that project to appropriate regions in the cortex

← Located in the centre of the brain

← Divided into nuclei

← Each nuclei receives info from specific senses and info is relayed to specific area of cerebral cortex

← Controls sleeping and waking

← Malfunctions – pain, tremor, amnesia, impairments of language, disruptions in waking / sleeping

← Schizophrenia – abnormal changes in the thalamus

- HYPOTHALAMUS: species survival – fighting, feeding, fleeing, mating

← Regulates emotions and stress reactions

← Interact with limbic system

← Located under thalamus

← Plays a role in sleep

← Dysfunction – narcolepsy – fall asleep often and at unpredictable times

MIDBRAIN

← Controls eye movement and coordination

- More important in non-mammals, where it’s main source of control for visual and auditory info

← Superior colliculi – vision and visual reflexes

← Inferior colliculi – hearing

← Reticular Activating System – RAS (extends to hindbrain) – regulation of consciousness (sleep, wakefulness, arousal, attention, heartbeat and breathing)

- RAS + Thalamus essential to having conscious awareness of / control over our existence

- BRAINSTEM – connects forebrain to spinal cord

- Consists of hypothalamus, thalamus, midbrain & hindbrain

- PERIAQUEDUCTAL GRAY (PAG) is in the brainstem – key for adaptive behaviours

- Simulation of PAG using excitatory amino acids or electrical current results in

← Aggressive confrontational response

← Avoidance or flight responses

← Heightened defensiveness

← Reduced reactivity – hopelessness after a defeat

← Brainstem will determine if someone is brain dead or not

HINDBRAIN – (MOPC)

MEDULLA OBLONGATA: Heart activity, breathing, swallowing, digestion

- Nerves cross over from right side of body to left side of brain and vice versa

- Located where spinal cord enters the skull and joins with the brain

- Contains part of the RAS (Reticular Activating System)

PONS: Relay station passing signals within the brain

- Latin for bridge

← Contains nerves that serve the face and head

CEREBELLUM “Little Brain”: Bodily coordination, balance, muscle tone

- Some aspects of memory for procedural movements

- Evolutionarily the oldest, most primitive part of the brain – and first part of the brain to develop prenatally.

Evolutionary trends:

- Humans have shown greater proportion of brain weight in relation to body weight

- Across span of development, brain to body weight proportion declines

- Increasing neural complexity of the brain

-

FOREBRAIN – CEREBRAL CORTEX – makes us human

- Forms a 1-3mm layer around brains surface - forming outer layer of the 2 halves of the brain

- Comprises 80% of the brain

- Creases on cerebral cortex comprise thee diff. elements

- a) Sulci (sulcus = singular) = small grooves

- b) Fissures – large grooves

- c) Gyri (gyrus = singular) = bulges between adjacent sulci / fissures

← Purpose of these is to increase the brains surface area

← Enables us to think, plan, coordinate thoughts, perceive visual and sound patterns and use language

← Grey matter – neural cell bodies

← White matter – white myelinated axons

← The brain is CONTRALATERAL – the left hemisphere controls the right side of body and right hemisphere controls the left

← There is some IPSILATERAL - (R to R / L to L) – odour info from right nostril (and some of the info from the R eye) goes to R side of brain

← Two hemispheres communicate directly with one another

← Two hemispheres connected by CORPUS CALLOSUM (neural fibres) – if cut – the 2 hemispheres cannot communicate – most functioning depends on integration of 2 hemispheres

HEMISPHERIC SPECIALISATION

← Marc Dax – noticed relationship between Left side of brain and language

← Broca’s Area – contributes to speech and pivotal to imitation

← Carl Wernicke – Wernicke’s Area – contributes to language comprehension

← Karl Spencer Lashley - father of neuropsychology

← Roger Sperry – Nobel Prize Winner – argues each side of the brain operates like a separate brain

← Humans with epilepsy have had severity of seizures reduced by having corpus callosum severed

SPLIT BRAIN PATIENTS

LEFT HEMISPHERE

← Language

← Important for movement, damage to same can result in APRAXIA – disorder of skilled movement Examines past experiences to find patterns – important for generating hypothesis

← Left process information analytically (piece by piece)

RIGHT HEMISPHERE

← Spatial visualisation and orientation

← Right hemisphere is ‘mute’ – little grammatical or phonetic understanding but has good SEMANTIC knowledge

← Right hemisphere damage results in deficits in following conversations and stories; can’t make inferences from context and can’t understand metaphorical or humorous speech

← Plays a primary role in self-recognition

← Right processes info holistically

LOBES OF CEREBRAL HEMISPHERES

← 4 Lobes

← Not distinct units but arbitrary anatomical regions, each with particular (interacting) functions

1. FRONTAL LOBE (Front of the head / face)

- Motor processing – primary motor cortex – execution of movement

- Higher thoughts – abstract reasoning, problem solving , planning, judgement

- Involved in sequences of thoughts / actions

- Critical in speech production

- Front of lobe = PREFRONTAL CORTEX = responsible for complex motor control and tasks that require integration of info. Over time

2. PARIETAL LOBE (Upper back portion)

- Primary somatosensory cortex

- Somatosensory processing – touch, pain, temp sense and limb position in relation to space occupied

- Consciousness and paying attention

3. TEMPORAL LOBE (Below the parietal)

- Under your temples

- Auditory processing and comprehending language

- Retention of visual memories

- Matches new things seen with visual memory

4. OCCIPITAL LOBE

- Visual processing

- Visual areas each specialized to analyse specific aspects of a scene – incl. colour,motion, location and form

- Some ipsilateral neural fibres

BRAIN =

- 1/40 of weight of adult

- Uses 1/5 of circulating blood

- 1/5 of available glucose

- 1/5 of available oxygen

BRAIN DISORDERS

1. STROKES:

← Cause vascular disorder

← Occur when flow of blood to the brain is disrupted

← Loss of cognitive functioning – nature of loss depends on are of brain affected

← ISCHEMIC STROKE: build-up of fatty tissue occurs in blood vessels over a period of years. A piece of tissue breaks off and gets lodged in arteries of brain

← HEMORRHAGIC STROKE: blood vessel in the brain suddenly breaks

← Blood spills into surrounding tissue – brain cells die as a result of lack of oxygen / nutrients or from rupture

← Typical symptoms:

← Numbness / weakness in face / arms / legs – on one side of the body

← Confusion, difficulty speaking, understanding speech

← Vision disturbance

← Severe headache with no known cause

2. BRAIN TUMORS / NEOPLASMS

← Occur in grey or white matter (more common)

← PRIMARY BRAIN TUMOR – Start in brain

← SECONDARY – start elsewhere in the body

← BENIGN – no cancer cells, can be removed without re-growth, but can cause cognitive impairment where the push against brain cells

← MALIGNANT – cancer cells, grow quickly – can break away and cause cancer in the rest of the body

← Symptoms:

← Headaches (worse in the am)

← Nausea / vomiting

← Changes in speech, vision, hearing

← Changes in mood, personality, ability to concentrate

← Problems with memory

← Seizures / convulsions

← Numbness in legs / arms

3. HEAD INJURIES

← CLOSED HEAD INJURIES: skull remains intact, but damage to the brain

← OPEN HEAD INJURIES: skull is penetrated

← Symptoms:

← Abnormal breathing

← Obvious wound / fracture

← Bleeding / blear fluid from nose, ears or mouth

← Disturbance of speech / vision

← Pupils of unequal size

← Dizziness / weakness

← Neck pain / stiffness

← Excessive vomiting

Chapter 3 – Perception

Perceptual processes – cognitive activities that allow us to attach meaning to sensory input

← Occur fast and effortlessly

← Perception not restricted to vision – it denotes the intake and interpretation of sensory information via any modalities

← The existence of perceptual illusions suggests that what we sense (in our sensory organs) is not necessarily what we perceive (in our minds)

The basics of vision

← Light passes protective covering – CORNEA

← Light enters centre of the IRIS via the PUPIL

← Passes through the CRYSTALLINE LENS – transparent membrane behind iris which can flex/relax to allow close or distance viewing

← Passes through VITREOUS HUMOR – gel like substance that is majority of the eye and provide support for the eye – provide REFRACTION: changes in direction and speed of light entering eye

← Refracted light focuses on RETINA: network of neurons extending over posterior surface of the eye: the receptor surface of the eye

← At the retina – electromagnetic light energy is converted into neuro electrochemical impulses

← Retina has three main layers of neural tissue

← 1st layer – outward facing GANGLION CELLS, axons of which constitute the OPTIC NERVE

← 2nd layer – INTERNEURON CELLS: i) AMACRINE CELLS + ii) HORIZONTAL CELLS – make lateral connections among adjacent areas of the retina iii) BIPOLAR CELLS – make dual connections forward and outwards to the ganglion cells and backward and inward to the 3rd layer of retinal cells

← 3rd layer – PHOTORECEPTORS – transduce light energy into electrochemical energy which is then transmitted to the brain

← 2 kinds of photoreceptors i) RODS – long, thin, highly concentrated in the periphery of the retina

← ii) CONES – short, thick, highly concentrated in the FOVEA region of the retina

← FOVEA = small thin region, size of pinhead, directly in line of sight.

← Each cone has own ganglion cell which gathers information from only one cone

← Rods on the periphery share ganglion cells, which gather info. From many rods

← Within rods and cones – PHOTOPIGMENT S – which react to light and transform electromagnetic energy into an electrochemical neural impulse that can be understood by the brain

← Neurochemical messages produced by rods and cones travel via bipolar cells to the ganglion cells

← Axons of ganglion cells form optic nerve

← Optic nerves of the 2 eyes join at the base of the brain to form the OPTIC CHIASMA

← Ganglion cells from nasal part of retina cross optic chiasma and go to opposite hemispheres of the brain

← Ganglion cells from the temporal area of the retina go to the hemisphere on the same side of the body

← Image on retina is inverted

← Ganglion cells go to thalamus to the primary visual cortex in the occipital lobe

← Visual cortex has processing areas for intensity, quality, colour, location, depth and pattern

← 2 separate vision systems –i) dim lights – depends on rods ii) vision in brighter light – cones

BASIC CONCEPTS OF PERCEPTION

Context of perception - “Tree falling in a forest and no-one around to hear it, does it make a sound”

i. DISTAL (EXTERNAL) object = tree

ii. Event imposes a pattern of information on an INFORMATIONAL MEDIUM = reflected light & sound waves, chemical molecules, or tactile information coming from the environment (sound of falling tree)

iii. When the information comes into contact with the appropriate sensory receptor of eyes, ears, nose, skin, mouth – PROXIMAL (NEAR) SIMULATION occurs (the action of the medium)

iv. Perception occurs when an internal PERCEPTUAL OBJECT in some way reflects the properties of the external world

Perceptual continuum

Distal object (vision) (informational medium (sound waves) (proximal simulation (sound waves conduction to receptor surface) ( perceptual object (falling tree)

← Sensory perception will never give exactly the same set of stimulus properties previously experienced

← Sensory adaption – receptor cells adapt to constant stimulation by ceasing to fire until there is a change in stimulation

← Through sensory adaption, we stop detecting the presence of a stimulus

← Because of sensory adaption in the retina, our eyes constantly making rapid movements which create constant changes in location of the projected image inside the eye

← Stimulus variation essential for perception

PERCEPTUAL CONSTANCIES

Occurs when our perception of an object remains the same, even when our proximal sensation of the distal object changes

SIZE CONSTANCY – Perception that object maintains size despite changes in size of proximal stimulus

Same object at two different distances – projects diff. sized images on retina

Depth cue affects how we perceive objects

Ponzo Illusion

SHAPE CONSTANCY – perception that an object maintains same shape despite changes in shape of proximal stimulus

An objects perceived shape remains the same despite changes in its orientation and hence it’s change of shape in the retinal image

Moller-lyer illusion

DEPTH PERCEPTION

Depth = distance from a surface

Proximal stimuli on your retina = 2 D projection of what you see

Perceptual cues aid in our perception of 3D world. Some cues can be seen with one eye alone, others need the use of both eyes

Depth cues are either MONOCULAR or BINOCULUR

|CUES FOR DEPTH PERCEPTION |APPEARS CLOSER |APPEARS FURTHER AWAY |

|MONOCULAR DEPTH CUES represented in 2D and seen with one eye |

|Texture gradients |Larger grains, further apart |Smaller grains, closer together |

|Relative Size |Bigger |Smaller |

|Interposition |Partially obscures other object |Is partially obscured by other object |

|Linear perspective |Apparently parallel lines seem to diverge as |Parallel lines seem to converge as they |

| |they move away from the horizon |approach the horizon |

|Aerial perspective |Images seem crisper and more clearly delineated|Images seems fuzzier, less clearly delineated |

|Location in the picture plane |Above the horizon, objects are higher in the |Above the horizon, objects are lower and above |

| |picture plane; below the horizon, objects are |the horizon, objects are higher |

| |lower in the picture plane | |

|Motion parallax |Objects approaching get larger at an |Objects departing get smaller at |

| |ever-increasing speed |ever-decreasing speed |

|BINOCULAR DEPTH CUES based on receipt of sensory info in 3D from both eyes |

|Binocular convergence |Eyes feel tug inward to nose as object gets |Eyes relax outwards to ears |

| |closer | |

|Binocular disparity |The closer the object, the greater the |Minuscule discrepancy between image seen by |

| |discrepancy between the image seen by left eye |left eye and image seen by right eye |

| |and image seen by right eye | |

|Binocular neurons in the brain integrate incoming information from both eyes to form depth info. |

OBJECT AND FORM PERCEPTION

What form does mental representation take?

1. View centred representation – what matters is the appearance of the object to the viewer – not the actual structure of object. Representation of object in relation to me

2. Object centred representation – individual stores a representation of the object, independent of its appearance to the viewer. Representation of the object in relation to the entirety of the object itself, independent of my position

3. Land-marked centred – information is characterised by its relation to a well-known / prominent item

The Gestalt Approach to form perception

The whole differs from the sum of its individual parts

← GESTALT LAW OF PRAGNANZ – we perceive any given visual array in a way that most simply organises the disparate elements into a stable and coherent form.

← We perceive a focal figure and other sensations are the background for the figure

← FIGURE = object perceived being highlighted

← GROUND = background

← Impossible to see both simultaneously

GESTALT PRINCIPLE OF SYMMETRY: Requires features to have balanced proportions around a central point

PROXIMITY – array of objects, we see those that are close to each other as forming a group ӧ ӧӧӧ ӧӧ ӧ

SIMILARITY – we group objects based on their similarity xoxo

xoxo

xoxo

CONTINUITY – we perceive continuous, smooth flowing forms rather than disrupted ones

= two images, one over the other – not joined in the middle

CLOSURE – we perceptually close up/complete objects

SYMMETRY – perceive objects as forming mirror images about their centre – we integrate symmetrical elements - see 2 sets of brackets, not 4 individual ones

PATTERN RECOGNITION SYSTEMS

FARAH Theory of a two–part system

← 1st system – recognition of parts of objects and in assembling parts into a whole (tyres, engine, boot = car)

← 2nd system – recognising large configuration – the car – not the parts it’s made up of

← 2nd system relevant in face recognition and recognition of a friend based on configurational system

← BUT familiar face uses 1st system to analyse features, enabling you to then recognise full face

← Facial recognition occurs in the FUSIFORM GYRUS of the temporal lobe

← Emotion increases activation within the fusiform gyrus. Thus –when naming / viewing an expression on a face / emotion, increased activation in the fusiform gyrus. When naming the person, deceased

← Autistic people have less active fusiform gyrus – they can learn to identify emotion, but this Is not an automatic process

← We have a perceptual tendency to see what is familiar, therefore knowledge of context improve accuracy of perception

THEORETICAL APPROACHES TO PERCEPTION

Direct perception – how do we connect what we perceive to what is stored in our minds

HOFFDING FUNCTION (Harald Hoffding) – Can perception be reduced to a simple view of associating what is seen with what is remembered

GIBSONS THEORY of direct perception

← We do not need higher cognitive processes to mediate between our sensory experiences and what we perceive.

← The info in our sensory receptors and sensory context is all that’s needed to perceive anything

← We are biologically tuned to respond to contextual info.

← Based on our analysis of the stable relationships among objects features and settings, we directly perceive our environment – AKA Ecological model

BOTTOM-UP & TOP-DOWN THEORIES – a complete theory of perception needs to encompass both theories

BOTTOM-UP THEORIES

← Data-driven / stimulus driven theories

← Theory that starts with the processing of low level features

A. TEMPLATE THEORIES

- Templates are highly detailed models for patterns we potentially might recognise – stored in our minds

- We recognise a pattern by comparing it with the template and making a match

- i.e. fingerprints / barcodes

- only exact match will do – so will not do in everyday situations

- to have, store and organise and retrieve so many templates is unwieldy

B. PROTOTYPE THEORIES

- Prototype = an average of a class of related objects or patterns which integrates all the most typical / frequently observed features of the class – is therefore highly representative of a pattern for which it is a model

C. FEATURE THEORIES

- We attempt to match features of a pattern to features stored in memory, rather than matching a whole pattern to a template / prototype

- Feature matching model = PANDEMONIUM (Oliver Selfridge) – “demons” with specific duties receive and analyse features of a stimulus

- IMAGE DEMON receives sensory input

- Retinal image passed onto FEATURE DEMON that decodes for specific features

- Matches are yelled out at COGNITIVE DEMONS who ‘shout’ out possible patterns stored in memory that conform to one/more features noticed by feature demon

- DECISION DEMON ‘listens’ for loudest shout in the pandemonium to identify the input

HUBEL & WIESEL RESEARCH

← Measured the responses of individual neurons in the visual cortex

← Mapped neurons to corresponding visual stimuli for particular locations in the visual field

← Specific neurons of visual cortex in the brain respond to varying stimuli presented to specific regions of the retina corresponding to these neurons

← A disproportionately large amount of the visual cortex is devoted to neurons mapped to receptive fields in the foveal region of the retina

← Most cells don’t respond to spots of light, the only become activated when they detect specifically oriented line segments

← These cells show a hierarchical structure in the degree of complexity of the stimuli they respond to

← As stimulus proceeds through visual system to higher levels in the cortex, the size of the receptor fields increases, as does the complexity of the stimulus required to prompt a response

← In some areas of the cortex, highly sophisticated complex cells fire maximally only in response to very specific shapes, regardless of size

← Separate neural pathways identified in the cerebral cortex for processing different aspects of the same stimuli = the WHAT AND WHERE PATHWAYS

← WHAT – descends from primary visual cortex in occipital lobe towards temporal lobe, colour, shape, identity of stimuli

← WHERE – ascends from occipital to parietal lobe, location and motion info.

STRUCTURAL DESCRIPTION THEORY (amplified feature matching theory)

BIEDERMANS RECOGNITION BY COMPONENT (RBC) THEORY

← Object – bricks, cylinders, wedges, cones and curved axis counterparts = 3-D GEONS (GEOMETRICAL IONS)

← We recognise objects by looking at edges of them and decomposing object into GEONS and then recomposing them into alternative arrangements

← GEONS are simple and view-point invariant (discernable from various viewpoints)

← Objects constructed from geons are easily recognisable from many perspectives, despite visual noise

Problem with RBC theory and bottom-up approach – How to account for the effects of prior expectations and environmental context (context effects)

TOP-DOWN APPROACHES

← Driven by higher level cognitive processes

← Existing knowledge

← Prior expectations that influence perception

CONSTRUCTIVE PERCEPTION AKA INTELLIGENT PERCEPTION – higher order thinking plays important role

← Perceive builds / constructs a cognitive understanding / perception of a stimulus

← Sensory info used as foundation for structure

← The world affects our perception but also the world we experience is actually formed by our perception – therefore perception is reciprocal with the world we experience

← According to constructivists – during perception we quickly form and test hypothesis regarding percept’s; percept’s based on 3 things:

i. What we sense – sensory data

ii. What we know – knowledge stored in memory

iii. What we infer – using high level cognitive processes, we consider prior expectations

Successful construction perception requires:

INTELLIGENCE and thought in combining sensory info with knowledge gained from previous experiences

- Context effects – influences of surrounding environment on perception

- CONFIGURAL SUPERIORITY EFFECT – objects presented in certain configurations are easier to recognise than object presented in isolation

- Extreme top-down position – underestimate the importance of sensory data, therefore extreme constructivists view of perception would be highly error prone

- Extreme bottom-down position would not allow for any influence of past experiences / knowledge on perception

DEFICITS IN PERCEPTION

AGNOSIAS & ATAXIAS

What / how hypothesis – spatial info about where an object is located is always present in visual info processing

AGNOSIA- severe deficit in ability to perceive sensory information (what pathway)

Individual has normal sensations of what is in front of them, but cannot recognise what they see

Caused by brain leisons / restricted oxygen to areas of the brain

Damage to the border of the temporal and occipital lobes

1. SIMULTAGNOSIA – individual unable to pay attention to more than one object at a time

2. SPATIAL AGNOSIA – difficulty negotiating everyday environment – get lost at home

3. PROSOPAGNOSIA – impaired ability to recognise human faces, functioning of right hemisphere fusiform gyrus implicated and damage to right temporal lobe

4. APPERCEPTIVE AGNOSIA – failure in object recognition linked to perceptual processing

5. ASSOCIATIVE AGNOSIA - Ability to represent objects visually but cannot use this information to recognise things

6. COLOUR AGNOSIA – inability to name colours without a corresponding loss in ability to perceive colours (see colour but has no name for it)

OPTIC ATAXIA - Damage to how pathway

Impairment in ability to use visual system to guide movement

Trouble reaching for things

ANOMALIES IN COLOUR PERCEPTION

← More common in men – genetically linked

← Cannot detect differences in colour

← Lifelong and doesn’t develop from injury

← True colour blindness = cannot see any colour at all = MONOCHROMACY

← DICHROMACY = Malfunction in one of the mechanisms for colour perception. The most common = red/green. People with dichromacy experience either of two syndromes:

i. PROTANOPIA – extreme form of red/green colour blindness. Cannot see long wavelengths

← Red = appear beige

← Greens = appear red

← PROTANOMALY – Less extreme

ii. DEUTERANOPIA – can’t see medium wavelengths – Greens

← DEUTERANOMALY – Less serious , can see red and green but not the way normal people do

← Less common = blue / yellow

← TRITANOPIA – can’t see short wavelengths – blues

← Blue / green confused and yellow disappear

← ROD MONOCHROMACY / AKA ACHROMACY no colour vision at all – cones are non-functional – everything is grey

AKINETOPSIA – A selective loss of motion perception. Motion appears as a series of snapshots

ACHROMATOPSIA – hereditary, absence of cones in retina – rely on rods for vision

CHAPTER 5 – MEMORY: MODELS & RESEARCH METHODS

(INPUT) ENCODING ( STORAGE ( RETRIEVAL (OUTPUT) = DYNAMIC MECHANISMS

MEMORY: means by which we retain and draw on past experiences to use that info. In the present

Encode: transform sensory data into a mental representation

Storage: keep encoded info in memory

Retrieval: pull out and use stored info

RECALL VS. RECOGNITION

Recall – produce a fact/word/ item from memory

← Expressive knowledge

← Recall tasks elicit deeper levels of info processing

Recognition – select / identify an item as being one learned previously

← Receptive knowledge (such as MCQ)

← Recognition memory better than recall

3 types of RECALL tasks

1. Serial recall – repeat items in a list exactly in the same order in which they were seen / heard

2. Free recall – repeat list items in any order, however you recall them

3. Cued recall – you must memorise a list of paired items, then when given one item in the pair, you must recall its ‘mate’

EXPLICIT MEMORY = consciously recall particular info

- Infants and older adults have poor explicit memory

DECLARATIVE KNOWLEDGE = YOU MUST RECALL FACTS

IMPLICIT MEMORY – draw on information in memory without consciously realising you do so - unconscious recollection

- Not affected by age

PRIMED: Facilitation of your ability to utilize missing information

PROCEDURAL KNOWLEDGE: non-declarative memory

- Learned skills and automatic behaviours – motor skill, riding a bike, driving – the ‘knowing how’ skill

TRADITIONAL MODELS OF MEMORY

Atkins and Shiffrin = three memory stores = hypothetical constructs, not directly measurable or observable but are mental models

1. Sensory Store – stores limited amts of info over brief time

2. Short term store – limited capacity and slightly longer time

3. Long term store – larger capacity, longer periods of time

SENSORY STORE – Visual / auditory / haptic (touch)

• Initial repository of info

ICONIC store – visual sensory register that holds info for short periods.

Info stored in form of icons, which represent something

(George) SPERLINGS DISCOVERY – Iconic store; how much info can we encode in a single brief glance at a set of stimuli?

• 3 rows, 4 symbols each

• Participants only need to remembers 1 row of symbols – row signalled by tone (low, med, high pitch)

• Amount remember / iconic duration - affected by time delay between tone and flash

• If cued immediately before/after display – remembered 9/12

• If cued 1 sec later – 4/12 remembered

• Therefore ICONIC store holds 9 items and info decays rapidly

• Verbal reporting may interfere with reports of iconic memory

• Erasure of info occurs if other info is superimposed on it, before there is enough time for the transfer of into to another memory state

• Also occurs with ECHOIC memory (auditory info)

SHORT TERM STORE

← Holds memories for 30 seconds to minutes

← Info stored acoustically rather than visually

← Capacity of 7 items plus/minus 2 (item is a digit or a word)

← MILLER – if we CHUNK together a string of numbers/letters into 7 meaningful items, we remember them

← When items have a large number of syllables, we can recall fewer items

← Delay / interference can cause our 7 item capacity to drop to 3 items

← Visual info also held in short term memory – 4 items.

← Storage depends on number of objects rather than number of features or spatial location

LONG TERM STORE

Memories stay indefinitely / possibly permanent

PERMASTORE – long term storage of info

Rely heavily on LTM for everyday life.

THE LEVELS OF PROCESSING MODEL

Postulates that memory does not comprise 3 stores – but rather varies along a continuous dimension in terms of depth of encoding

← There are an infinite number of LEVELS OF PROCESSING (LOP) at which items can be encoded

← No boundaries between levels

← Processing is the key to storage – the level at which info is stored will depend on how it’s encoded

← The deeper the level, the higher the probability the item can be retrieved

← Logically connected words (dog + animal) recalled more easily than concretely connected (dog + leg)

← LOP framework also applies to visual stimuli (faces )

SELF-REFERENCE EFFECT

← Participants show high levels of recall when asked to relate words meaningfully to themselves by determining whether the words describe them

← Highest level of recall with self-descriptive words – better able to associate positive than negative descriptions of ourselves

← Everyone has a self-schema – an organised system of internal cues regarding our attributes, personal experiences. We can elaborately encode info about ourselves more so than other topics

← When we generate our own cues – we have a higher level of recall

← 2 strategies for elaborating the encoding

o WITHIN ITEM elaboration = elaboration in terms of characteristics, at various LOP

o BETWEEN ITEM elaboration = encoding done by relating each items features, at various LOP, to features of items already in memory

AN INTEGRATIVE MODEL: WORKING MEMORY

Holds only the most recently activated, or conscious portion of LTM

Moves the activated elements into/out of brief temp storage

Working memory – coordinates sights and sounds into meaningful arrangements

Alan Baddeley – Integrative model of memory - views LOP framework as an extension of the working memory model – 4 elements

1. VISUOSPATIAL SKETCHPAD – holds visual images

2. PHONOLOGICAL LOOP – holds inner speech for verbal comprehension and acoustic rehearsal

- Subvocal rehearsal – puts info into memory in the first place

- Phonological storage – holds info in memory

- Amount of info stored is limited

- Without loop – acoustic info decays after 2 seconds

3. CENTRAL EXECUTIVE – coordinates attentional activities and governs responses

- Critical to working memory – it is the gating mechanism that decides what info to process further and how to process it

- Decides what resources to allocate to memory and related tasks

- Involved in higher order reasoning, comprehension and central to human intelligence

4. EPISODIC BUFFER – limited capacity

- Binds info from subsidiary systems and long term memory into a unitary episodic representation

- Integrates info from visual spatial and phonological so that it makes sense to us.

MULTIPLE MEMORY SYSTEMS

Working memory model consistent with notion that multiple systems may be involved in the storge and retrieval of information

2 separate explicit memory systems

SEMANTIC MEMORY – stores general world knowledge / facts not unique to us

EPISODIC MEMORY – stores personally experienced events or episodes (learn a list of words)

“Saw Joe at the dentist yesterday” – Episodic

Name of person – semantic

Memory systems interact

MEMORY

DECLARATIVE (EXPLICIT) NON DECLARATIVE (IMPLICIT) NON ASSOCIATIVE (HABITUATION)

SEMANTIC (FACTS) EPISODID (EVENTS) PROCEDURAL SKILLS PRIMING CONDITIONING

A CONNECTIONIST PERSPECTIVE

CONNECTIONIST PARALLEL DISTRIBUTED PROCESSING (PDP) MODEL

- Key to knowledge representation lies in the connection between various nodes, not in each individual node

- Activation of one node may prompt activation of additional nodes

- A PRIME is a node that activates a connected node

- The activation of this node = PRIMING EFFECT

- Connectionist models – working memory comprises the activated portion of long term memory and operates through some amount of parallel processing

- Spreading activation involves parallel activation (priming) of multiple links among nodes within the network.

MEMORY IN THE REAL WORLD

← Storehouse metaphor – leads to question of quantity

← Lab setting allows control over variable of quantity

← Real world approach calls for correspondence metaphor – memory is a vehicle for interaction with the world – therefore question = accuracy in representing events

EXCEPTIONAL MEMORY & NEUROPSYCHOLOGY

OUTSTANDING MEMORY: MNEMONISTS - exceptionally keen memory ability

Mnemonic of visual imagery – convert word into visual image for memory recall

SYNESTHESIA – experience of sensations in a sensory mode, different from the sense that had been physically stimulated

Sound converted automatically to visual image

We more easily encode info into our LTM that is similar to info already stored there

HYPERMNESIA – A process of producing retrieval of memories that would have seem to have been forgotten

Achieved by trying many diverse retrieval cues to unearth a memory

The risk of hypermnesia – create a new memory, believing it’s the old one, rather than retrieving a genuine old memory

AMNESIA – Severe loss of explicit memory

1. RETROGRADE AMNESIA – occur with concussion

← Events prior to concussion not well remembered

← When memories return, they start from distant past and progressively return up to the time of the trauma

2. INFANTILE AMNESIA – can’t recall events that happened when very young – before 5 years

← Accuracy of reported childhood memories questioned

3. ANTEROGRADE AMNESIA –the inability to remember events that occur after a traumatic event

← HM – recall event before operation, but lost ability purposefully to recollect any new memories after the operation – lives suspended in eternal present

Amnesia and explicit memory distinction

← Explicit memory is typically impaired in amnesia

← Declarative knowledge (knowing that)- consciously recalled info affected

← Non-declarative knowledge (implicit memory) - drive a car – not affected

Amnesia and neuropsychology

Dissociations of functions – people with specific lesions in the brain show absence of a particular function

But – functions can be shaped by multiple structures or regions – therefore we cannot determine the specific cause/effect relationship between a given structural lesion and a particular memory deficit

Double dissociations – people with diff. kinds of neuropathological conditions show opposite patterns of deficits i.e.

People with lesions in left parietal lobe have inability to retain info. In STM, but no impairment in LTM

Lesions in medial (middle) temporal regions show normal STM of verbal material, but show serious inability to retain new verbal material in LTM

ALZHEIMERS DISEASE

← Causes dementia and progressive memory loss

← Definitive diagnosis only possible after death: Brain shows:

1. PLAQUES – dense deposits found outside neural cells

2. TANGLES – pairs of filaments that twist around each other, found in cell body and dendrites of neurons. Shaped like a flame

← Progression is irreversible, but it can be slowed using:

- ARICEPT – slows destruction of the neurotransmitter acetylcholine

- EBIXA (MEMANTINE) – inhibits a chemical that overexcites brain cells

← Early-onset Alzheimer’s – Familial – linked to genetic mutation

← Earliest signs of onset – impairment of EPISODIC memory – can’t remember things that were learned in a temporal / spatial context

← As disease progresses – semantic memory goes

← Non-declarative memory spared till end

THE ROLE OF THE HIPPOCAMPUS AND OTHER STRUCTURES

- Cerebral cortex plays important role in memory in terms of Long term storage of info

- HIPPOCAMPUS important for explicit memory of experience

- Plays a role in the encoding of declarative info – the function of integration and consolidation of separate sensory info

- Involved in transfer of newly synthesized info into long term structures supporting declarative knowledge

- Role in complex learning and recollection of info

- AMYGDALA – role in memory consolidation, especially where emotional experience is involved.

Alcohol consumption show to disrupt activity of serotonin – therefore it impairs formation of memories

Severe prolonged use of alcohol = KORSAKOFF’S SYNDROME = anterograde amnesia and some retrograde

The more emotionally charged an experience / memory is – the greater the probability the memory will be later retrieved

- Basil ganglia – controls procedural knowledge

- Cerebellum - Role in classic conditioned responses and contributes to cognitive tasks

Chapter 6 – Memory processes

← Events that are unusually memorable (9/11) distort people’s perception of risk - they are rated more likely than they are and less memorable causes are underestimated

← Research:

← Memories are frequently inaccurate and sometimes completely wrong

← We tend to fill in missing info in memory with info that fits our believe system, or was acquired post event

← Very little relationship between memory accuracy and confidence – we are often highly confident that we are remembering an event the way it was – but memory is actually partially / wholly wrong

ENCODING AND TRANSFER OF INFO

FORMS OF ENCODING

SHORT TERM STORAGE

← We primarily Use ACOUSTIC CODE – we encode visually presented letters by how they sound not how they look and some secondary SEMANTIC CODE – based on words meaning

← We visually encode temporary / fleeting info – which is more vulnerable to decay

LONG TERM STORAGE (flexible)

← Errors made when retrieving words from STM – usually reflect confusion in sound

← Most info in LTM is primarily SEMANTICALLY ENCODED, but not exclusively – also use acoustic and visual

← People move more info into LTM when using semantic encoding strategy

TRANSFER OF INFO FROM STM TO LTM

← Means of moving depends if info is declarative (facts & events) or non-declarative (procedural and knowing how)

← CONSOLIDATION: Make connection / association between new info and what we already know and understand. Integrate new data into existing schemas of stored info

← Stress impairs memory functioning but can enhance consolidation of memory through release of hormones

← During process of consolidation – memories are susceptible to disruption and distortion.

← To preserve / enhance integrity of memories – use METAMEMORY STRATEGIES = Reflecting on own memory processes with a view to improvement

← METACOGNITION = ability to think about / control our own process of thought and ways of enhancing our thinking

REHEARSAL – repeated recitation

- Over – aloud and obvious

- Covert – silent and hidden

Memory for info depends how it’s acquired

← DISTRIBUTED PRACTICE: learning sessions spaced over time give good memories

← Spacing Effect - The greater the distribution over time, the more one remembers over long periods

← MASSED PRACTICE: sessions crammed together in short time = poor memory and info decays quickly.

- REM sleep affects learning – better learning with increases in the proportion of REM stage sleep after exposure to learning situations

- Insomnia – trouble with memory consolidation

- HIPPOCAMPUS – important structure for memory – increased hippocampus activity during sleep, after learning session and improved performance when tested

- Increased activity of hippocampus = low levels of acetylcholine

- Increased levels of acetylcholine = impaired memory consolidation for declarative memory

- Procedural not affected by acetylcholine levels

- Therefore – rapid learning system in hippocampus which is activated during sleep – rapidly learned memories become integrated into our more permanent LTM

- Consolidation makes memories less likely to undergo interference / decay – but once memory called back into consciousness, it may return to a more unstable state and memory that was consolidated may be interfered with / decay. To prevent this loss, RECONSOLIDATION takes place on newly recalled memory – same process as consolidation but is completed on previously encoded info

TOTAL TIME HYPOTHESIS – Amount of learning depends on amt of time spent mindfully rehearsing info

2 constraints:

1. Full time allotted for rehearsal must be used for that purpose

2. Rehearsal should include various kinds of elaboration / mnemonic devices to enhance recall

← ELABORATIVE REHEARSAL – elaborate items to make them more meaningfully integrated – then move to LTM

← MAINTENANCE REHEARSAL – repetitiously rehearse items to be repeated. Info is in STM. Without elaboration – can’t be organised and moved to LTM

ORGANISATION OF INFORMATION

Adults tend to spontaneously cluster items into categories – which aids memorisation

MNEMONIC DEVICES – Techniques to memorize

1. Categorical clustering: organise list of items into categories – shopping lists into fruits, meats, dairy

2. Interactive images: create interactive images that link isolated words in a list – create story using words

3. Pegword system: associate each new word with a word on a previously memorised list and form interactive images between two words – one – bun, two – shoe, 3 – tree / apple, sock, scissors =

Apple in a bun, sock in a shoe, scissors cutting tree

4. Method of Loci: visualise walking around a known area with distinctive landmarks and link landmarks with specific items to be remembered

5. Acronyms: Devise word / expression in which each of it’s letters stands for a word/concept. IAM PACK = acronym for mnemonic devices

6. Acrostic: form a sentence, rather than a word, to help you remember new words

7. Keyword system: Form interactive images that link the sounds and meaning of a foreign word with sound and meaning of a familiar word.

Turkish – very = cok - chock a block – very full

← When choosing a method for encoding information and subsequent retrieval, one should consider the purpose for recalling the info

← Use of mnemonic devices involves metamemory

← REMINDER: external memory aid – shopping list

← FORCING FUNCTIONS: Physical constraints that prevent us from acting without taking the item to be remembered into consideration – leaning book to take with you against exit door

← RETROSPECTIVE MEMORY: memory for the past

← PROSPECTIVE MEMORY: Memory for the thing we need to do/remember for the future – a to do list / tie string on finger

- Monetary reinforced improved prospective memory

- Retrospective and Prospective memory decline with age but we retain more prospective due to use of external cues

- In lab – older adults show decline in prospective

- Outside lab – older perform better than younger adults – perhaps due to greater reliance on strategies to aid remembering as we age.

RETRIEVAL - From STM

List of digits presented = Positive Set

List of digits not presented = Negative Set

Parallel vs. Serial processing

← Parallel – simultaneous handling of multiple operations

- All items retrieved at one time, NOT one at a time

- Response time would be the same – regardless of size of positive set

- All comparisons done at once

← Serial – operations done one after another

- Digits retrieved in succession

- Response time would increase as digits are retrieved

Exhaustive vs. Self-terminating processing

If information processing is serial, there are 2 ways to access stimuli

← Exhaustive serial processing: check test digit against all digits in positive set–even if match found ½ way through list

← You would take the same amount of time to find any digit

← Self-terminating serial processing: test digit checked against only those needed to make a response

← Response time would increase linearly as a function of where test digit was located in positive set

← The later the serial position, the longer the response time

RETRIEVAL from LTM

← Memory failures can be attributed to a failure to recall, rather than storage failures

← Categorisation affects retrieval – better recall for categories of info, opposed to free-recall / random order

← Availability of Items = presence of info stored in LTM

← Accessibility of items = degree to which we can gain access to available info. Memory performance depends on accessibility of items

← DELIBERATELY ATTEND TO NEW INFO (If you define info in your own words) – and try to understand it = DEEP PROCESSING of info

← Copy info = shallow processing

← Giving own examples improves transfer of new info from working memory to LTM by making connections between existing and new info

← Examples from life experience – more like to remember info due to connection to ourselves

Processes of forgetting and memory distortion

INTERFERENCE – competing info causes us to forget something

DECAY – passage of time causes us to forget

Interference theory

• Forgetting occurs because recall of certain worlds interferes with recall of other words

• TRIGRAM: 3 consonants

• Retention interval is the time between presentation of last word and start of recall phase.

• Trigram forgotten after 18 seconds if participants can’t rehearse it and have to count backwards during interval. Therefor interference of STM

RETROACTIVE INTERFERENCE (INHIBITION) –

Caused by activity after we learn something but before we have to recall it

Learn ( Activity ( Recall (activity=retroactive interference–interferes with our ability to remember info previously learned)

PROACTIVE INTERFERENCE –

Interference occurs before the learning of the ‘to be remembered’ material

Activity ( Learn ( Recall

Prior knowledge and expectations affects recall. People bring their existing schemas into a memory task, which affects the way they recall what they learn

SERIAL POSITION CURVE – represents probability of recall of a word, given its serial positioning in a list

Recall is better for words at / near the end of the list

Recency effect - subject to proactive interference – recall is 2nd best for words near the beginning

Primacy effect – subject to retroactive interference – recall is poorest for middle items as they have both types of interference

• Amount of proactive interference climbs with increases in length of time between encoding and retrieval

• As amount of prior learning increases, the proactive interference increases

• Proactive interference associated with frontal cortex ( it activates the Brodmann area 45 in the left hemisphere, which is likely to be involved in the binding of items into meaningful groups

• All info does not contribute to proactive interference

• Learning numbers – performance declines as you progress, switch to words and performance rebounds – release from proactive interference

You will remember words

1st - at / near the end

2nd – near the beginning – subject to proactive interference (activity (interference)– learn – recall)

3rd – middle – has proactive and retroactive interference (learn – activity – recall)

DECAY theory – information forgotten due to disappearance of memory trace, not displacement

BARTLETT – participants learned a text and then recalled it (the war of the ghosts story)

Recall was distorted to render the story more comprehensible to themselves

CONSTRUCTIVE NATURE OF MEMORY

A. Reconstructive – uses various strategies for retrieving original memory traces and then rebuilding original experience

B. Constructive – prior experiences affects how we recall things and what we recall from memory.

i.e. participants read ambiguous passage that has 2 meanings

participants omitted diff. details depending on what they thought the passage was about.

AUTOBIOGRAPHAL MEMORY

• Memory of an individual’s history is constructive

• One remembers a construction or reconstruction of what happened

• Subject to distortions

• Middle aged adults will remember events from youth and early adulthood better than the recent past

• DIARY studies (Linton) – keep detailed autobiographies, and recorded experiences. Linear rate of forgetting events – a constant rate of forgetting was found

• Serial position effect occurs – recall is better at beginning and near end, and more important ones better recalled

• If one has a positive self-esteem, you remember more positive events

• Negative self-esteem – remember negative events

MEMORY DISTORTIONS – SCHACTERS 7 SINS OF MEMORY

Saying something happened makes you more likely to think it really happened

1. TRANSIENCE – memory fades quickly

2. ABSENT-MINDEDNESS – forget what you’re looking for

3. BLOCKING – into on tip of tongue – can’t retrieve it

4. MISATTRIBUTION – can’t remember what was seen, heard, read. Think they see things that they didn’t – eyewitness testimony clouded by what we think we should have seen

5. SUGGESTIBILITY – to suggest to someone they saw something, they then think they remember seeing it

6. BIAS – person currently experiencing pain are more likely to remember pain in the past – whether they experienced it or not

7. PERSISTANCE – remember something as consequential which, in broad text – inconsequential

i.e. many successes and one failure – remember failure better

EYEWITNESS MEMORY

• Eyewitness identification is the single largest factor leading to false convictions

• People very susceptible to distortion due to constructive nature of memory

• We can be lead to construct false memory due to suggestibility

• In line-ups – eyewitness assume perp is in the line-up- therefore distractors must be carefully chosen

• Eyewitness ID is weak when identifying people of a race other than their own – due to problems encoding faces

• ID and recall affected by witness’s stress levels – increased stress = decline in accuracy of recall and ID

• Children’s recollections particularly susceptible to distortion and to suggestive questioning

• The younger the child- the less reliable the testimony .

• They will tell the adult what they think they want to hear and believe they recall things that others have said they have seen

REPRESSED MEMORIES

Memories that are alleged to have been pushed into the unconscious due to the stress they have caused.

They are inaccessible but can be dredged out.

- Therapist might inadvertently plant ideas – creating false memories

- Showing implanted memories are false hard to do

- No compelling evidence the repressed memories exist – no clear conclusion

ROEDIGER MCDERMOTT PARADIGM (work of Deese) – effects of memory distortion in a lab

← Participants get a list of 15 words, strongly associated with a critical, but non-presented word. i.e. 15 words relating to the concept of sleep – but not the word sleep.

← The recognition rate for the non-presented word was comparable to the presented words.

← Thus – people weak in distinguishing what they have heard from what they’ve not heard.

SOURCE-MONITORING ERROR – person attributes a memory derived from one source to another source

JOHNSON AND LINDSAY RESEARCH – people have difficulty in source monitoring – figuring out the origins of a memory

Possible explanation of increased false recognition = SPREADING ACTIVATION = every time an item is studied you think of items related to that item. i.e. word NAP – think of bed, sleep, cat. Therefore source monitoring error occurs – you think of an ‘activated ‘word not the original

CONTEXT EFFECTS ON ECODING & RETRIEVAL

• Cognitive contexts for memory influence memory processes of encoding, storing and retrieval

• Existing schemas provide cognitive context which make integration and organisation easy – they fill the gaps when given partial / distorted info

• Expertise enhances confidence in our recollected memories

• Perceived clarity – vividness of detail of the experience and context enhances confidence in recall

• Recollection of the context of the learning experience = increased activation of the hippocampus

• Events with emotional stimuli – increased activation of the amygdala – leads to enhancement of the explicit / declarative memory

• Electrical stimulation of either hippocampus or amygdala can lead to recall / hallucinations of autobiographical memories

FLASHBULB MEMORY: memory of an event so powerful that person remembers that event as vividly as if it were preserved on film

← Emotional intensity may enhance likelihood of recall, keenly and accurately

View – memory becomes flashbulb when:

- Memory trace is important - It’s surprizing - Has emotional effect on individual

View – rehearsal – frequently retell / contemplate experience

View- flashbulb memory perceptually rich, not immune to distortion

← Moods &state of consciousness provide context for encoding that affects later retrieval of semantic memories. Therefore when we encode semantic info in a particular mood we’l more readily retrieve that info when in that state again

← Depressing effects of drugs and alcohol on memory is greater than the facilitating effect of recalling something in the same state as when encoding it.

← Mood = happy = retrieve happy. Sad = retrieve sad.

← External contexts affect our ability to recall – we are better able to recall info if we are in the same physical context as the one in which we learned it.

← ENCODING SPECIFICITY – how items are encoded has a strong effect both on how and how well items are retrieved

← Recognition memory is better than recall. Recognition says if you have seen the word

← Recall – generate the word and then mentally confirm if it appears on a list

← Watkins and Julving – 24 paired associates i.e. ground – cold / crusty – cake

- Learn to associate each response (cold) with its stimulus word (ground)

- When given the stimulus word – the cued recall of words increased.

- Stimulus is better cue for the word then the word itself = ENCODING SPECIFICITY

- When individuals generate their own meaningful cues – they are much more potent

MEMORY DEVELOPMENT AND METACOGNITIVE SKILLS

- Older children – greater processing resources and can hold more info for active processing

- Can organise info into increasingly large and complex chunks and can hold more chunks in working memory

- Metacognitive skills of older children – understanding and control of cognitive processes

- For children between 4 and 5 year s- there is no clear distinction between appearance and reality.

- External memory aids, rehearsal etc. comes naturally to adults but it’ a learned strategy

- Young children don’t spontaneously use strategies and lack inclination to use them when they know about them – they lack meta-memory skills (cognitive monitoring; awareness of your own mind and degree of understanding)

- Culture, experience, and environmental demands affect use of memory enhancing strategies

- Western children – more practice using rehearsal for remembering isolated bits of info.

- Non-western children – memory enhancing strategies that rely on special location and arrangement of objects

- Self-monitoring is a bottom up process

- Self-regulation is a top down process of central executive control over planning and evaluation

- Metacognitive development is the acquisition of a theory of mind – an understanding how the mind operates. Related to verbal intelligence, communication abilities and number of siblings

- Late childhood and most of adulthood – memory abilities remain constant

- Decline as we age as a result of changes in the frontal striatal system – changes in white matter and depletion in neurotransmitters

Chapter 11 – PROBLEM SOLVING AND CREATIVITY

• The problem solving cycle

• Working in groups facilitates problem solving

• Solutions reached by groups often better than those reached by individuals

• Most notable when members have a variety of ability levels

1. Problem identification – Identify the goal / existence of the problem

2. Definition of a problem – crucial to define and represent problem correctly. If not – less likely to solve it

3. Constructing a strategy for problem solving – plan strategy: analysis – break it down into manageable elements or synthesis – put various elements together into something useful

Divergent thinking – diverse assortment of alternative solutions

Convergent thinking – narrow down and converge on single best answer

4. Organising information about a problem - in a way that enables you to implement your strategy

5. Allocation of resources – time, money, equipment, space.

Expert problem solvers give more mental resources to the big picture planning (global planning) – more time deciding on how to solve the problem and less time solving it

Novel problem solvers give more time to detail oriented planning (local planning)

6. Monitoring problem solving – check up along the way

7. Evaluating problem solving – once you have finished.

• Flexibility in steps necessary

• No one optima sequence - can go back and forth / skip / change

• Emotion can influence the way we implement the problem solving cycle

• High emotional IQ can positively influence the problem solving

TYPES OF PROBLEMS

Well-structured / well defined

- Clear path to solution

- Application of a formula

- Move problems = require series of moves to reach final goal state (hobbits and orcs)

- Model of problem solving: Problem solver (AI / human) must view the initial problem state and the goal state within a problem space

- Problem space = the universe of all possible actions that can be applied to solving a problem, given any constraints that apply to the solution of the problem

- Fundamental strategy – divide problem task into a series of steps, each step involves rules for procedures that can be implemented

- Set of rules organised hierarchally into programmes containing internal levels of subprograms called ‘routines’ and ‘subroutines’

- Sublevel programs = ALGORITHMS = sequences of operations that may be repeated over and over that guarantee the solution to the problem

- i.e. computer provided with well-defined problem and appropriate hierarchy (program) of operations organised into procedural algorithms – computer can calc. all possible operations and combinations of operations within the problem space and determine best possible sequence of steps

← Unlike PC’s – human mind does not do high speed computations of numerous possible combinations; working memory limited to considering a few possible operations at a time

← Humans use MENTAL SHORT CUTS for solving problems – HEURISTICS = informal, intuitive, speculative strategies that sometimes lead to effective solutions and sometimes don’t.

← We can store several heuristics in LTM that we can apply to a variety of problems

HEURISTICS USED IN PROBLEM SOLVING

1. Mean-end analysis: problem solver continually compares current state and goal state and takes steps to minimise the difference between the two states

2. Working forward: start at the beginning and tries to solve problem from start to finish

3. Working backward: start at the end and work backwards

4. Generate and test: generate alternative courses of action, not necessarily systematically, and then check in turn whether each course of action will work

ISOMORPHIC PROBLEMS – the structure is the same, only the content differs

PROBLEM REPRESENTATION

How a problem is presented is a major determinant of ease of solving

← Tower of Hanoi – problem solver must use a series of moves to transfer a set of rings from the first of three pegs to the third of the three pegs, using as few moves as possible

← Physically different sizes of rings facilitated mental representation of restrictions

← Mental processing speed shows no correlation with success in solution

ILL STRUCTURED PROBLEMS AND ROLE OF INSIGHT

← Ill structured problem – do not have a clear well-defined problem space

← Difficult to construct mental representations for modelling problems

← INSIGHT - sudden understanding of a problem or strategy that aids a solution

← INSIGHT PROBLEMS – to solve problem you need to see it in a novel way, restructure the representation

← Right hippocampus critical in formation of insightful solution

Different explanations of insight

← Gestalt Psychologists = importance of the whole, not the collection of the parts. Therefore they perceive the problem as a whole

← PRODUCTIVE THINKING (Max Wertheimer) – insightful – involves insights that go beyond bounds of existing associations, see problem in a new light

← REPRODUCTIVE THINKING: based on existing associations involving what is already known

Insight may result from (no evidence)

← Extended unconscious leaps in thinking

← Greatly accelerated mental processing

← Short circuiting of normal reasoning process

NOTHING SPECIAL VIEW

- Insight is the extension of ordinary perceiving, recognising , learning and conceiving

- The significant product of ordinary thinking process

NEO-GESTALTIST VIEW

Routing problems – solvers show accuracy in their ability to predict own success prior to attempt.

- Metcalfe – participants show incremental feelings of warmth as they draw closer to reaching correct solution

Insight problems – solvers show poor ability to predict own success and where pessimistic about ability

- Participants show no incremental feelings of warmth

THE THREE PROCESS VIEW – 3 kinds of insights which correspond to three different processes

1. SELECTIVE ENCODING INSIGHT – Distinguishing relevant from irrelevant information

2. SELECTIVE – COMPARISON INSIGHT – involves novel perception of how new info relates to old info. Compare existing info with new knowledge

3. SELECTIVE COMBNATION INSIGHTS – taking selectively encoded and compared bits of relevant info and combining it in a novel and productive way (hat rack – find novel way to put together and use tools)

← INSIGHT EXPERIENCE - a special process involving an abrupt mental restructuring

← INSIGHT – an understanding that may involve either special insight experience or normal cognitive processes that occur incrementally rather than suddenly

← Routine problems may demand insight, but they may not require insight experience

← Insight problems require insight experience

← Insight need not be a sudden ‘ah-ha’ experience – often occur gradually over time

← Sleep can help produce a solution

OBSTACLES AND AIDS TO PROBLEM SOLVING

Factors that hinder problem solving

i. MENTAL SET – frame of mind involving an existing model for representing a problem

AKA Entrenchment – an entrenched mental set – fixate on strategies that normally work well in solving many problems, but does not work well for that particular problem.

ii. FUNCTIONAL FIXEDNESS – the inability to realise the something known to have a particular use may be used for performing other functions. Prevents us from solving new problems by using old tools in a novel way

iii. STEREOTYPES – Belief that members of a social group have particular characteristics. Generalisation based on limited observations

NEGATIVE AND POSITIVE TRANSFER

← Transfer = carry- over of knowledge of skills from one problem situation to another

← Negative transfer – solving an earlier problem makes it harder to solve a later one

← Positive transfer – solution of an earlier problem makes it easier to solve new problem – transfer of a mental set can be an aid to problem solving. During positive transfer you apply a strategy solution that worked well for a particular problem, when you are trying to solve a similar problem

TRANSFER OF ANALOGIES

← When domains / contexts of two problems are similar- participants more likely to see and apply the analogy

← Be aware of being misled by associations between two things that are analogically different

← What matters in analogies is not the similarity of the content, but how closely their structural systems of relationships match

← TRANSPARENCY – people see analogies where they don’t exist due to similarity of content – may lead to negative transfer between non-isomorphic problems.

INCUBATION – putting problem aside without consciously thinking about it – minimise negative transfer

Beneficial effects of incubation:

- When we no long keep something in active memory, we let go of unimportant details and keep only meaningful aspects which we can reconstruct

- More recent memories become integrated with existing memories – association of mental sets may weaken

- As time passes, new stimuli may activate new perspectives on the problem, which may weaken effects of the mental set

- Internal / external stimuli may lead problem solver to see an analogy between current and another problem , therefore can find comparable solution / apply know solution

- Solver in low cortical arousal (in shower or bed) allow increase in attention span and working memory capacity – may allow remote cues to be perceived.

Neuropsychology of planning in problem solving

• Planning saves time and improves performance

• FRONTAL LOBES – involved in high level cognitive processes – essential, together with PREFRONTAL CORTEX, for planning for complex problem solving tasks

• Traumatic brain injury = problem solving and planning ability decline

← Experts assumed to have developed ways of thinking and reasoning effectively - use of knowledge is a crucial factor.

← Knowledge interacts with understanding in problem solving

← Learners do better when presented with new material in a coherent way

← High knowledge group – better with material of low coherence which forces them to pay attention

← Organised knowledge systems more important to experts

← Schema of experts – large, highly interconnected units of knowledge, organised according to underlying structural similarities among knowledge units

← Schema of novice – small disconnected units of knowledge organised according to superficial similarities

← Experts use visual representation to solve wide range of mathematical problems, whether or not they had spatial component. Ability to apply visual rep. to variety of problems allows greater flexibility and increased likelihood of solution being found.

← Novice – use visual representation only with problems with spatial component (geometry)

Setting up problems – expenditure of time

← Verbal protocol = statement made by problem solver – lead to increased problem solving ability

← Experts send proportionately more time determining how to represent a problem than do novices, but spend less time than novices actually implementing the strategy or solution

← Expert – works forward from information given. “What do I know” to “What do I need to find out”

← More time on how to match given info. with their existing schema

← Novice – works backwards from unknown info to given info and use means-end analysis. They consider more possible strategies

← Experts only turn to means-end-analysis if they are unable to retrieve appropriate strategy in existing schemas.

EXPERTS:

• Have more, better, organised knowledge

• Use knowledge more effectively

• Schemas involve greater declarative knowledge about a problem domain

• Involve more procedural knowledge

• More accurately predict the difficulty of solving problems

• Monitor strategies more carefully

AUTOMATIC EXPERT PROCESSES – practice allows experts to automatize various operations

i. SCHEMATIZATION – developing rich, highly organised schemas

ii. AUTOMATIZATION – consolidating sequence of steps into unified routines that require little / no conscious control

• Using these two processes, experts shift burden of problem solving from limited capacity of working memory to LTM – therefore more efficient and accurate in problem solving

• Novice – use working memory to hold multiple features and various alternate strategies , leaving little working memory for monitoring accuracy and progress

← Reading involves two distinct processes (Wagner & Stanovich)

← Conversion from orthographic (relating to visual appearance of letters) code to phonological (sound) code

← Increased / extensive exposure to text enhances the orthographic to phonological conversion process by increasing automaticity.

← BUT – automaticity of experts could hinder problem solving when they tackle problems that differ structurally from problems normally encountered

← Initially novices perform better

Innate talent and acquired skill

← Practice makes perfect

← Practice must be deliberate / focused and emphasise acquisition of new skills

← Interaction between innate abilities modified by experience accepted

← Skills domain heavily dependent on nurture

← Wisdom – partly knowledge based, the knowledge one used to make wise judgements is a result of experience

← Experts perform at superior levels due to prediction skills – looking ahead for next move / play / sign

← Genetic heritage affects acquisition of expertise

INVESTMENT THEORY OF CREATIVITY

← Convergence of multiple factors distinguishes highly creative individuals

← Creative individuals takes a buy low / sell high approach to ideas

← Buying low = creator sees hidden potential in ideas that are presumed by others to have little value

← Creator develops idea into creative contribution and is recognised.

← Creator then sells high and moves onto looking for more undervalued ideas – stays a step ahead

← Extraordinary creative productivity may be rare because it relies on so many variables coming together, in the right amounts, in a singer person

← Variable do not show a linear relationship to creativity (increase in characteristic does not mean increase in creativity)

NEUROSCIENCE OF CREATIVITY

• Prefrontal regions active during creative process – regardless if there is effort or spontaneity

• Broadmanns area 39 active during unrelated word lists story production, but not with semantically related words

Types of creative contributions – Sternberg 8 Kinds

1. REPLICATION – show a given field is where it should be

2. REDEFINITION – an effort to redefine where field currently is – a new point of view

3. FORWARD MOVEMENT – move field forward in same direction it is moving and contribution takes field to a point where others are ready for it to go

4. ADVANCED FORWARD MOVEMENT – contribution moves the field beyond where others are ready for it

5. REDIRECTION – new and diff. direction

6. REDIRECTION FROM POINT IN THE PAST – move field back to where it once was (reconstruction of the past) so that field can move onward from that point

7. STARTING OVER – move field to a diff. and as not yet reached starting point. Then moves field in a diff. direction from that point

8. INTEGRATION – move the field by putting together aspects of two or more past kinds of creative contributions that were formerly viewed as distinct / opposed – now synthesised.

QUALITATIVELY DISTINCT

QUANTITATIVELY DIFF. WITHIN EACH TYPE

CHARACTERISTICS OF EXPERTS (Green and Gilhooly)

1. Experts remember better

2. Employ different problem solving strategies

3. Better and more elaborated problem representations

4. Experts superiority based on knowledge, not basic capacity

5. Become experts through extensive practice

← Drawback of expertise – may suffer from functional fixedness when confronted with tasks / problems that differ structurally from those why are accustomed to.

← Automatisation frees cognitive resources because it reduces the amount of cognitive control needed to monitor the problem solving process – it helps to shift the burden of control from working memory to LTM

• Computer based approaches of problem solving – PC program embodies explicit theories about the processes that humans make use of when they solve a particular problem.

• One can then test structure of problem and steps needed to solve it

• Drawback – one might read too much into the successful construction of a computer simulation independent proof needed that program does simulate human cognitive process

Expertise leads to more analytical algorithmic approaches to problem solving in which forward planning is used but NOT feasible to work out a procedure from start to finish.

Means-end analysis uses subgoals/intermediate goals to progress to the solution state of a problem

Remains best technique for approaching complex problems – even by experts

CHAPTER 12 – JUDGMENT AND DECISION MAKING – used to select from among choices or to evaluate opportunities

← FALLACY – erroneous reasoning

← Goal of reasoning = draw conclusions deductively from principals or inductively from evidence

← DEDUCTIVE – apply general laws of physics to reach a specific conclusion

← INDUCTIVE – reading statistics to find out about large field of info – from specific to general

CLASSICAL DECISION THEORY – economic perspective – using mathematical models for human behaviour

ECONOMIC MAN AND WOMAN

Decision makers fully informed regarding all possible options and all possible outcomes of decision options

They are infinitely sensitive to subtle distinctions among options – can evaluate the diff. between 2 diff. outcomes

They are fully rational in regard their choice of options – make choice to maximise something of value

SUBJECTIVE EXPECTED UTILITY THEORY

← Goal of human action is to seek and maximise human pleasure = positive utility and

← To avoid and minimise pain (negative utility) – done using 2 calculations

SUBJECTIVE UTILITY – calculation based on individuals judged weightings of utility (value) –not objective criteria

SUBJECTIVE PROBABILITY – calculations based on individual’s estimate of likelihood rather than objective statistical computations

← Diff. people would give different subjective positive or negative utilities to diff. aspects of matter in question – depending on individual frame of reference

← According to subjective expected utility theory -: each person will go through steps:

- Multiply each subjective probability (estimate of likelihood) by each subjective positive utility

- Subtract each subjective probability of each subjective negative utility

- Decision reached based on relative expected values – many subjective variable taken into account.

- A persons subjective expected utility is based on subjective estimates of probability and subjective weightings of costs and benefits

People seek to reach well-reasoned decisions based on 5 factors

1. Consideration of all possible known alternatives

2. Use of maximum amount of available information

3. Careful, if subjective, weighing of potential costs (risks) and benefits of each alternative

4. Careful (subjective) calculation of the probability of various outcomes – given that certainty of outcomes cannot be known.

5. Maximum degree of sound reasoning based on 1 – 4

SATISFICING

← Humans do not always make ideal decisions – usually include subjective considerations

← We show BOUNDED RATIONALITY – rational within limits

← Decision making strategy – SATISFICING =consider options one by one, then select an option as soon as we find one good enough to meet our minimum level of acceptability

← We do not consider all possible options and then work out which option, in the universe of options, will maximise our gains and minimise our losses

← Therefore we consider the minimum possible number of options needed to arrive at a decision that will satisfy our minimum requirement – decide for first acceptable alternative that comes along.

ELIMINATION BY ASPECTS

Too many alternatives – then use process of elimination by aspects

Eliminate alternatives by focusing on each alternative aspect, one at a time

- Focus on one attribute / aspect of various options

- Form minimum criterion

- Eliminate all options that don’t meet that criterion

- Remaining options given a 2nd aspect with a minimum criterion – again eliminate

- Continue with sequential process of elimination of options until single option remains

- Weed out alternatives – one aspect at a time

NATURALISTIC DECISION MAKING

Mental state and cognitive pressure experienced by ER doctor cannot be reproduced in a lab

Field of study based on decision making in natural environments

Cognitive, emotional and situational factors allowed for

GROUP DECISION MAKING

Group – enhances effectiveness of decision making and problem solving

• Group benefits from expertise of each member

• Increase in resources and ideas

• Improved group memory over individual memory

Characteristics of successful decision making in groups:

- Small groups

- Open communication

- Members have common mind set

- Members identify with the group

- Agree on acceptable group behaviour

- Diverse members share more info

Disadvantages: Group think

- premature decision making as a result of members attempting to avoid conflict

- caused b anxiety, when anxious will explore less options

Conditions leading to groupthink (Janis)

- isolated cohesive and homogeneous group empowered to make decisions

- objective and impartial leadership absent

- high levels of stress impinged on process

Six symptoms of group think:

i. Close-mindedness

ii. Rationalization

iii. Squelching of dissent – those who disagree are ignored

iv. Formation of a mind guard – one person self-appoints keeper of group norm

v. Feeling invulnerable – feel they must be right, given intelligence of members

vi. Feeling unanimous

Antidote for groupthink

- encourage constructive criticism

- Seek input from outsiders

- Form subgroups to consider alternatives

HEURISTICS & BIASES

- Shortcuts in thinking that lighten cognitive load of making decisions

- Allow for greater chance of error

REPRESENTATIVENESS

Judge the probability of an uncertain event according to:

- How obviously it is similar to / representative of the population from which it’s derived

- The degree to which it reflects the salient features of the process by which it is generated

Gamblers fallacy = Representative heuristic

- Mistaken belief that probability of random event is influenced by previous random events

- Gambler loses 5 consecutive times – believe he’s due to win the 6th time

- People use the representative heuristic as they fail to understand the BASE RATE

- Base rate is the prevalence of an event / characteristic within its population of events / characteristics

- Use base rates to improve decision making

AVAILABLITY HEURISTIC – make judgement based on how easily we can call to mind what we perceive as relevant instances of the phenomenon

i.e. how many words in text ending in ……ing and how many ending in ……n.

Greater availability of the former – leads to higher estimates of the former

CONJUNCTION FALLACY – higher estimates given for a subset of events than for the larger set of events containing the subset

INCLUSION FALLACY - Individual judges greater likelihood that every member of an inclusive category has a particular characteristic, than that every member of a subset has that characteristic

JUDGEMENT PHENOMENA

1. Anchoring and adjustment heuristic – people adjust their evaluation of things by means of certain reference points called end-anchors

Anchor renders an estimate that influences the final estimate

2. Framing effects – the way options are presented influences the selection of an option – we tend to choose options that demonstrate risk aversion, when faced with potential gains – rather a small certain gain opposed to large uncertain gain

3. Illusory correlation – we tend to see particular events / attributes and categories as going together because we are predisposed to do so.

4. Overconfidence – an individual’s overvaluation of their own skills, knowledge or judgement

Results in poor decisions based on inadequate info and ineffective strategies

5. Sunk-Cost fallacy – decision to continue to invest in something simply because no one has invest in it before and on hopes to recover ones’ investment – attempt to justify money spent

Opportunity cost – price paid for availing yourself to an opportunity

6. Hindsight Bias – when looking at a situation retrospectively, we believe we can see all the signs and events leading up to a particular outcome

“Take the best” Heuristic – identify single most important criterion to you in making the decision – this is

a fast and frugal heuristic (FFH) – based on a small fraction of info, decision made rapidly

NEUROSCIENCE OF DECISION MAKING

← Prefrontal Cortex

← Anterior Cingulate Gyrus is activated during decision making process

← Amount of gain associated to a decision affects amount of activation observed in the parietal region

← Anterior cingulate cortex involved in consideration of potential rewards an in comparison and weighing of possible solution

DEDUCTIVE REASONING

← Reasoning from one/more general statements to reach a logically certain conclusion - a specific statement

← Based on logical propositions – an assertion / statement (T or F)

← Premise – propositions about which arguments are made

← Deductive reasoning helps people connect propositions to draw conclusion

← Determine the truth of a premise, given a definite conclusion

CONDITIONAL REASONING

← Reasoner must draw conclusion based on if/then proposition

← IF = ANTECEDENT condition P is met, THEN CONSEQUENT event Q follows (If P then Q)

o “if student studies hard, then they get high marks”

← DEDUCTIVE VALIDITY – logical soundness of reasoning – does not always equate with the truth

← If P, then Q.P, therefore Q = MODUS PONENS ARGUMENT

o ‘If students eat pizza, they score high marks. They eat pizza, therefore they score high marks”

← In modus ponens – reasoner AFFIRMS THE CONSEQUENT

← If P, then Q. Not Q, therefore not P = MODUS TOLLENS ARGUMENT

← Reasoner DENIES THE CONSEQUENT

DEDUCTIVE FALLACIES

Denying the antecedent - If P, then Q. Not P therefore not Q

Affirming the consequent – If P, then Q. Q, therefore P

|Type of Argument |Conditional Proposition |Existing condition |Inference |

|Deductively Valid Inference | | | |

| | | | |

|Modus Ponens (Affirming the | | | |

|antecedent) |If you are a mother, then you have |You are a mother (P) |Therefore you have a child (Q) |

| |a child P ( Q | | |

|Modus Tollens (Denying the | | |Therefore you are not a mother (not|

|consequent) |If you are a mother, then you have |You don’t have a child (not Q) |P) |

| |a child P ( Q | | |

|Deductive Fallacies | | | |

| | | | |

|Denying the antecedent |If you are a mother, then you have |You are not a mother (Not P) |Therefore you don’t have a child |

| |a child P ( Q | |(not Q) |

| | |You have a child (Q) | |

|Affirming the consequent |If you are a mother, then you have | |Therefore you are a mother (P) |

| |a child P ( Q | | |

THE WATSON SELECTION TASK

Set of two-sided cards

Number on one side and letter on the other

“If card has a consonant on one side (P) , then it has an even number on the other side (Q)

PG 502

Pragmatic Reasoning Schemas = general organising principals or rules related to particular goals

- General and broad – can be applied to a wide variety of specific situations

- Prior beliefs matter in reasoning, they help us deduct what might be reasonably true – particular situations / contexts activate particular schemas

- Young person driving – activates your permission schema for driving – law says you must be 16 to drive, then deduce person is 16

EVOLUTIONARY VIEW OF COGNITION (CUMMINS)

← We must consider what kinds of thinking skill would provide a naturally selective advantage for humans in adaptability to our environment across evolutionary time.

← How did caveman think? How has evolution influenced human cognition?

← (Cosmides) we possess a schema acquisition device: facilitates our ability to glean important info from our experiences & helps us organise info into meaningful frameworks

← Highly flexible and specialised for selecting info that will effectively aid us

← Distinctive adaption show by caveman is social exchange, therefore evolutionary development of human cognition should facilitate acquisition of schemas related to social exchange. There are 2 types of inferences that social exchange schemas facilitate:

← Inference of cost- benefit relationship

← Inference that help detect when someone is cheating in a particular social exchange

SYLLOGISTIC REASONING

Syllogism – deductive arguments that involves drawing conclusions from 2 premises

A syllogism comprises a major premise, a minor premise and one conclusion (2 terms)

LINEAR SYLLOGISM

← Two premise describe a particular relationship between two items

← One item is common to both premises

← Subject = 1st term of major premise

← Common Term = middle term, used once in each premise

← Predicate – 2nd term of minor premise

← Relationship among terms in linear

|PREMISE |FIRST TERM (SUBJECT) |LINEAR RELATIONSHIP |2ND TERM (PREDICATE) |

|Premise A |You |Are smarter than |Your best friend |

|Premise B |Your best friend |Is smarter than |Your roommate |

|Who’s smartest |You |Are the smartest | |

|Deductively valid, conclusion follows logically |

1. Solved spatially – mental representation of linear continuum (your name above roommate in mental list)

2. Semantic model – using propositional representation

← Combined 1 + 2 to solve syllogisms

CATEGORICAL SYLLOGISMS – 2 premises and a conclusion

← Premise states something about the category membership of the terms

← Each premise contains two terms

← Middle term common to both premises (pianist)

← Each term represents all, some, none of the members of a particular class / category

← One term is a member of a category, indicated by the other term

- All psychologists are pianists (category)

- All pianists are athletes

- Therefore all psychologists are athletes – follows logically from premise

← Conclusion is false as premises are false

← Subject = psychologist, middle term = pianists, predicate = athletes

OBSTACLES AND AIDS TO DEDUCTIVE REASONING

Heuristics in syllogisms

i. Overextension errors – overextend the use of strategies that work in some syllogisms

ii. Foreclosure effects – fail to consider all the possibilities before reaching a conclusion

iii. Confirmation Bias – seek confirmation rather than disconfirmation of what we already believe (doctor may interpret set of symptoms supporting a diagnosis, without fully considering all possible alternatives)

← Mood affects syllogistic reasoning

← Sad mood – pay more attention to detail, therefore do better in syllogistic tasks

← Neutral mood – perform between 2 extremes

INDUCTIVE REASONING – based on observations – cannot reach logically certain conclusion

← Moving from the specific to the general

← Involves reasoning where there is no logically certain conclusion

← Forms basis of empirical method – we must always consider probability and must state conclusions in terms of likelihood

← People use inductive reasoning –

- Helps them become increasingly able to make sense out of greater variability in their environment

- Helps them predict events in their environment thereby reducing uncertainty

← We reach inferences by generalising some broad understandings from a set of specific instances – observe a few birds, and infer birds fly = generalised knowledge

Inductive reasoners use heuristics

- Representativeness

- Availability

- Law of large numbers

- Unusualness – when 2 unusual events co-occur, we assume they are connected in some way

Reasoning by Analogy

“Fire is to asbestos as water is to ………..vinyl” - Reasoner must deduce relation in 1st two items (resistance)

CHAPTER 13 – HUMAN INTELLIGENCE

← Intelligence involves capacity to learn from experience

← Ability to adapt to surrounding environment

← Metacognition = understanding and control of own thinking process + culture =

INTELLEGENCE = the capacity to learn from experience, use metacognition processes to enhance learning and ability to adapt to surrounding environment. It may require different adaptations within different social and cultural contexts

IMPLICIT Theories = unstated conceptions of intelligence

EMOTIONAL INTELLIGENCE – the ability to perceive and express emotion, assimilate emotion in thought, understand and reason with emotion and regulate emotion in self and others

SOCIAL INTELLIGENCE – ability to understand and interact with other people

CULTURAL INTELLIGENCE – a person’s ability to adapt to a variety of challenges in diverse cultures

MEASURES AND STRUCTURES OF INTELLIGENCE

1 – low level psychophysical abilities, sensory activity, physical strength, motor coordination

2 – higher level judgemental abilities – thinking

GALTON – psychophysical skills; weight discrimination, pitch sensitivity, strength

ALFRED BINET – judgement is key to intelligence

- Direction – knowing what has to be done and how 3 elements of intelligent thought

- Adaption – customising a strategy and monitoring

- Criticism – ability to critique own thoughts

BINET and SIMON – determine mental age – average level of intelligence at a given age

STERN – Intelligence Quotient (IQ) = MA / CA x 100

- Ratio of MA to CA = ration IQ

STANFORD – BINET INTELLIGENCE SCALE (VQFS)

1. Verbal reasoning

- Vocab comprehension

- Absurdities

- Verbal relations

2. Quantitative Reasoning

- Number series

- Quantitative – solve arithmetic word problems

3. Figural / Abstract reasoning

- Pattern Analysis

4. Short term memory

- Memory for sentences, digits, objects

DAVID WECHSLER SCALES

← WAIS 111 – adult intelligence scale

← WISC – IV – Wechsler intelligence scale for children

← WPPSI – Wechsler preschool and primary scale of intelligence

3 SCORES – VERBAL, PERFORMANCE AND OVERALL

5. VERBAL SCALE

- Comprehension – social knowledge

- Vocab

- Information

- Arithmetic – solve arithmetic word problems

- Digit span

- Similarities – how are 2 concept similar

1. PERFORMANCE SCALE

- Object assembly

- Block design

- Picture completion

- Picture arrangement

- Digit symbol

Wechsler intelligence is not just represented by a test score, it’s used in relating to people, being effective and managing our lives

WAIS – RN – Wechsler adult intelligence Scale revised as a neurological instrument – used to assess intellectual abilities of people with brain injuries

FACTOR ANALYSIS

Statistical method for separating a construct (intelligence) into a number of hypothetical factors / abilities that are believed to form the basis of individual differences in test performance

Based on correlation – the more highly two tests are correlated, the more likely they are to measure the same thing

SPEARMAN: THE ‘G’ FACTOR

Intelligence can be understood in terms of 2 kinds of factors

- A single general factor pervades performance

- A set of specific factors involved in performance on only a single type of ability test – narrow application

- The general ‘g’ factor is key to intelligence – the result of mental energy

THURSTON: PRIMARY MENTAL ABILITIES

Core of intelligence resides in 7 factors – primary mental abilities

i. Verbal comprehension

ii. Verbal fluency

iii. Inductive reasoning

iv. Spatial visualisation

v. Number

vi. Memory

vii. Perceptual speed

GUILFORD: THE STRUCTURE OF INTELLECT (SOI)

← Includes up to 150 factors of the mind

← Intelligence = a cube that represents the intersection of 3 dimensions

OPERATIONS: mental processes – memory, evaluation

CONTENTS: kinds of terms, semantic, visual

PRODUCTS: kinds of responses required – unites, classes and implications

CATTELL, VERNON & CARROLL: HIERARCHICAL MODELS

Cattell - General intelligence has two major sub-factors

1 – Fluid ability – speed, accuracy of abstract reasoning Decline with

2 – Crystallized ability – accumulated knowledge and vocab age

Within is more specific factors

Vernon – a general division between practical –mechanical and verbal – educational abilities

Carroll – Hierarchy of 3 strata

← Stratum I – narrow specific abilities (spelling, speed of reasoning)

← Stratum II – Various broad abilities (fluid and crystallized intelligence – includes learning, memory, processes, visual and auditory perception, verbal fluency and speed

← Stratum III – A single general intelligence

Information processing theories

← Study how people mentally manipulate what they learn and know about the world

← Speed and accuracy of info processing important factors in intelligence

- Inspection time – amount of time to inspect item and make decision about them

- Choice Reaction Time – the time it takes to select one answer from several possibilities (speed of neuronal conductions). Higher IQ = faster

- Lexical access speed = speed with which we can retrieve information about words stored in our LTM “AA, Ab, Aa” Match in name and match physically (how they look)

- Difference in speed between 2 tasks = a measure of speed of lexical access

- Students with lower verbal ability take longer to gain access to lexical information than students with higher verbal ability

Working Memory – critical component of intelligence

← Measure of working memory can provide prediction of scores on tests of general ability

← Ability to store and manipulate info in working memory important aspect

Componential Theory

Components – mental processes used in performing tasks such as analogies, series problems and syllogisms

i.e. translate sensory input into a mental representation - transforming one conceptual representation into another or into motor output (see and do)

Componential analysis – breaks down reaction time and error rates on these tasks, in terms of processes that make up the tasks

Component processes:

- Encoding terms of the problem

- Inferring relations among terms

- Mapping inferred relations to other terms, which would be presumed to show similar relations

- Applying previously inferred relations to the new situations

Lawyer: client :: Doctor: patient

← Global planning – encoding the problem and formulating a general strategy for attacking it

← Local planning – forming / implementing strategies for details of task (implementing)

More intelligent people spend more time on global planning, which increases likelihood that overall strategy will be correct and less time on actual implementation (local planning)

GARDNER MULTIPLE INTELLIGENCES - Intelligence comprises multiple independent constructs

8 distinct intelligences that are independent of each other (but are interacting)

1. Linguistic

2. Logical mathematical Each one a separate intelligence

3. Spatial Modular view of the mind, abilities can be isolated

4. Musical as emanating from distinct modules of the brain

5. Bodily – Kinaesthetic

6. Interpersonal

7. Intrapersonal

8. Naturalist

STERNBERG: THE TRIARCHIC THEORY

Intelligence – 3 aspects, analytical, creative, practical abilities

Practical – apply, use, utilise

Analytical Creative

Analyse, compare, evaluate Create, invent, design

These three aspects deal with the relation on intelligence to:

1. Internal world of the person – processing info using

- Metacognition – higher order executive processes

- Performance components – lower order processes used for implementing commands

- Knowledge acquisition components – process for learning how to solve problem in the first place

2. How intelligence relates to experience

- How prior experience may interact with components

- Novel tasks demand more intelligence

3. How intelligence relates to external world

- Adapting to existing environments

- Shaping existing environments to create new ones

- Selecting new environments

An intelligent person does not necessarily excel in all aspects

They know their strengths and weaknesses and find ways to capitalise on strengths to compensate / correct their weaknesses

ARTIFICIAL INTELLIGENCE – The study of how to make computers do the things which people do better

← Computer simulations of human intelligence

← Computer systems that use optimal methods to solve tasks

Computers must be programmed to behave as though they were thinking – programmed to simulate cognitive processes

Programs tell computers how to respond to new information

The TURING TEST

A test by which a human could assess the intelligence of a respondent

- Can an observer distinguish the performance of a computer from that of a human?

- Conducted with a PC, a human and an interrogator

- Interrogator has two difference conversations with an interactive computer program

- Goal – which is a person communicating through a PC and which is PC itself – if interrogator is unable to distinguish, then computer passes Turing test

Goal may be to exceed human performance - how well can the PC perform its assigned task?

“BRUTE FORCE” – evaluate large number of possible moves, many of which human would never consider – IBM chess program ‘deep blue’

LT (LOGIC THEORIST) – designed to discover proofs for theorems in elementary symbolic logic

GENERAL PROBLEM SOLVER (GPS) Newall – solved problems using means-end analysis

Solves problems by successively reducing the difference between the present state and goal status

SHRDLU – Terry Winograd – commanded a robot arm manually to manipulate various blocks in a block world

ELIZA (Joseph) – nondirective psychotherapist – goal it to elicit patients feelings and reflect feelings back to patient

PARRY (Colby) – Paranoid patient

Expert Systems – programs that can perform the way an expert does in a specific domain

Attempts to simulate performance in one domain

← MYCIN – used for detecting and potentially treating certain bacterial infections – contains 500 rules (if/then statements)

← INTERNIST – diagnoses a broad spectrum of diseases, but illustrates the bandwidth fidelity problem – the wider the spectrum of problems to which AI addresses itself, the less reliable it’s likely to be

← DENDRAL – helps scientists identify the molecular structure of newly discovered compounds

Absence of Intuition (Dreyfus)

← Intuition is found in hunches - that distinguishes experts from those with book knowledge

← Computers excel in mathematical and deductive aspects of thinking, but not intuitive

SEARLES CHINESE ROOM ARGUMENT

← Man locked in room – he knows no Chinese

← Given Chinese document to translate

← Given 2nd batch of Chinese script and set of rules for translating Chinese to English

← Given 3rd batch – rules for formulating responses to questions raised in first batch

← Man then responds to 1st batch in Chinese

← But he has no real understanding, he is simply following a set of instructions

← Situation captures the ‘symbol processing’ behaviour of digital computers – PC does not have any real understanding of the symbols it processes

← PC uses pre-established connections that make it seem intelligent

THE SYSTEMS REPLY

← While man doesn’t understand Chinese, the whole system (human, room, pen, instructions) show understanding – the man is just part of the system, which does understand the writing

THE ROBOT REPLY

← Program placed in robot that can interact with its environment, creating causal connections between symbols and things they represent, therefore robot could acquire genuine understanding

AI programs embody theories about intelligence – therefore of interest to cognitive psychologists who are trying to understand the factors underlying human intelligence

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Frontal

Parietal

Occipital

Temporal

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