Who is wilhelm wundt
- Father of experimental psychology
- Founded one of first labs for research
- 19th C
What is wundtian experiment? Shown?
Delay in stimulus and report - speed of attention, 0.1s delay
Issues w introspection
- Not always reliable
- Possible biases
- Not all mental activities transparent
- Not for children and animals
What is behaviourism
- Countermovement to introspection
- Everything we do = behaviour
- 1st half 20th C
- Classical conditioning
- Salivation by dogs at sight of feeder
- Stimulus-response associations
- Animal us instrumental in changing environment
- Thorndike: cat in puzzle box learns to solve
- Law of effect. Repeat good outcome, avoid bad
- Operant conditioning
- Language = verbal behaviour
- Operant conditioning chamber
- Controlled env allows study if how to modify behaviour
- Criticised skinners behaviourist approach to language
- Syntax, only minor variation (poverty of stimulus)
- Implies some language is innate
View of mind mid 20th C
- Info processing device
- Performs computational functions
Mind v brain - Pythagoras
Brain is organ of mind + temple of soul
Mind v brain - Plato
Soul is immortal, moves body to body
Mind v brain - Aristotle
Seat and source of sensation is heart
- Dualism of mind/brain
- I think therefore I am
- Mind and body interact via pineal gland
Modern alternative to dualism
- Mind is what brain does
- Allows psychology
System is protected against total wreckage
Loss of ability to recognise objects
Specific language impairment
Inability to recognise faces
Deficit in musical pitch processing, music memory + recognition
- Documenting 2 patients who have complementary impairments
- Suggests 2 mental domains are xarried out in different brain systems
P (stats) = ?
- Chance of obtaining a result like ours under assumption null hypothesis (H0) is true.
- If P < P value for significance (e.g. 0.05), accept H1, reject H0
Why P = 0.05?
- Compromise between cost + benefit
- Accepts 1/20 significant outcomes actually due to chance
- Measuring time taken to carry out mental processes
- Pioneered by Donders
Problematic to measure mental states. Measure what instead?
- Measure electrical activity along scalp w electrodes
- Avg out noise, analyse waveforms
ERP for faces? (EEG)
Event related potential: N170
fMRI and PET
- Detect increases in cerebral blood flow in response to mental activity
- Good for localising activities
Detection of simple properties
Interpretation of sensory signals
Receptors in retina types + pigment
- Rods (120mil) and cones (7mil)
- Rhodopsin (photosensitive)
Functioning or retinal receptors in low/birght light + colour/blacknwhite
- Rods: low light, not sensitive to colour
- Cones: bright light, sensitive to colour (peak sensitivity to r/g/b)
Output of cones depends on?
- White coded as equal output of rgb receptors.
Local computations of connections between receptors and optic nerve:
- Photoreceptors + bipolar xells: response to illumination is graded
- Amacrine + horizontal cells: compare + contrast signals from adjacent photoreceptors
- Ganglion cells: generate action potentials + form optic nerve (= 1mil ganglion cells)
Structures in visual cortex extract info about:
Shape, colour, position, motion etc.
Hubel + Wiesel
ID via single cell recording: simple cells found to respond to line/edge in illuminatkon reaching particular retinal region
1st stage of object recog:
Segmentation parsing: grouping of visual features
Figure v ground
- Fundamental distinction
- Assignment ambiguous, reversible
Gestalt principle of grouping
- Grouping of elements to make a figure
- E.g. by similarity, proximity, connectedness
Ambiguous figure, demonstates automatic construction of 3D shape from 2D image.
Cues to depth perception
(binocular vision), relative height + size, perspective convergence, texture gradient.
Depth perception: innate?
- Baby behaviour suggests yes
- + For some animals e.g. goats
Only 3/36 babies willing to move onto deep side - depth perception innate
How is ambiguity of many aspects of visual images resolved?
Via implicit assumption that objects are stable and unchanging.
- Neisser 1967
- Templates are fixed models for classifying objects, best template match outputted.
- Pattern recog based on global similarity match between sensory input + stored templates.
Arguments against template theories
- Completeness issue (R vs P), position, rotation, slant, size, font.
- Doesn't work for handwriting.
- Issues w changes in viewpoint, quantification of similarity.
Feature matching theory. +1Adv
- Object recog based on ID of features in visual array.
- Objects can be defined in terms of their component features.
- Adv: limited no. of features gives large no. of objects
Features (feature matching theory) need to:
- Discriminate effectively between alternatives
- Shouldn't be redundant w other features
- Ensure minimal feature set w max efficiency
pros feature matching theory
Physiological evidence for low-level visual feature analysis: Hubel + Weisel single cell recording in vis cortex of cat
cons feature matching theory
- Font variation too much
- How to describe complex objects in terms of low-level visual features
What viewpoint do template and feature matching assume is used?
What is an object-centred viewpoint
- Object is perceived in coordinate system centred on object
- Uses objects axes of elon.gation and symmetry to create reference frame, allows measurement of relative positions of components.
Recognition by components
- Beiderman, 1987
- Separate objects into geons
- Mental representation of object consists of geons + spatial relations (attachment relations)
What are geons?
- Simple 3D shapes e.g. cylinders, cones, wedges etc
- Realistic demands on vis system
Evidence for recog by components (Beiderman)
- Obj recog relies on attachment
- Deletion of vertices therefore decreases ID accuracy
Issues w geon theory
- Represents some objects e.g. horse + cow v similarly
- How vis system distinguish faces
- Doesn't work well for natural objects
Machine recog - Deep learning?
Neural networks, improved performance recently
Inversion effect (faces)
- Faces are much more difficult to recog when inverted than other onjects
- Facial recog is more holistic - rely on whole face - can't recog face when split up
Can recall/recognise thousands of faces, often having only seen once.
What is dichotic listening task for attention
- 2 diff messages transmitted to each ear
- Participant must shadow one message, ignore other.
- Asked about unattended trial: mostly unaware, physical attributes only.
Broadbent' filter model represents what?
Attentional selection representation
Cocktail party phenomenon?
- Participants of dichotic listening task can report name on unattended channel
- Highly pertinent stimuli capture attention
Why does name capture attention - Moray Cocktail Party
High relevance and freq of occurrenceHigh permanent priority - low threshold
Treismen - dichotic listening task
- Fragments from unattended reported if congruent w context of attended
- So unattented processed to some extent
- Expectations lowered threshold, meaning processed if fit into context of attended
- Attention is selective filter (physical -> permanent priorities -> current priorities -> meaning)
- Expectations temporarily lower threshold of words in mental dictionary
Attentuation bottleneck according to Broadbent, Treisman
- Before pattern recog
- Unattended only processed if threshold low
Attentuation bottleneck according to Deutsch + Deutsch
- All sensory info processed to level of meaning
- Output into STM, lost quickly
- Selection for conscious awareness after analysis
Evidence for late selection theories (attenuation model) - Subliminal perception
Briefly presented prime words are semantically processed and affect (prime) processing speed of subsequent semantically related target words
Evidence for late selection theories (attenuation model) - Negative priming
Ignoring a stimulus slows down subsequent redirection of attention to that stimulus
Shift of research perspective of attention bottleneck mid 1970s - central assumption
- Performance in any non-trivial task is costly and requires mental effort
- Kahneman - Capacity theory
Capacity theory (Attention)
People have limited capacity pool of attention to carry out mental activities - not bottleneck
What determines availability of attentional resources
- Individual differences/dispositions
- Momentary intentions
Multitasking - test capacity theory
- Johnson and Heinz
- Speed of a primary task (press button when light flashes) is affected by secondary task (shadowing spoken words)-> reaction time cost
- Early selection mode (physical condition) requires less capacity than late selection mode (semantic condition)
Posner and Snyder - Automaticity
Mental processes are automatic or conscious/controlled
- Demo of automaticity
- Worded colours in different colour ink, tasked to name ink
- Massive interference when word miscues response
- (Reading-automatic)(Naming colours-requires effort)
Magic no. 7 (+/-2)
- Individuals hold ~7 items in STM
- Capacity largely independent of nature of items
Common STM measuement task?
Primary + regency effects?
- Digit span task
- Primary: assumed to reflect contribution of LTM
- Regency: assumed to reflect contribution of STM
E.g. of double dissociation between STM and LTM
- Milner-epilepsy: hippocampus removed, defective LTM learning, anterograde amnesia (inability to acquire new knowledge), normal STM
- KF: brain damage, normal LTM, impaired STM (digit span reduced)
Dual task experiment: performance adversely effected by concurrent load, increase in reasoning time but v low error. Shows?
STM not as central to complex tasks as assumed
Working memory model
- Baddeley and Hitch
- STM made up of VSS and PL (+Central executive)
What is the central executive of the STM?
- Integrates info in STM
- "Anodal" - not tied to particular type of code
- Regulates info flow between peripherals
- Constrained by available capacity
Cognitive control using central executive allows:
negotiation of various, often competing, demands, schemata and habits
VSS (STM) specialises in
- Temporary holding + processing of visual + spatial codes
- Remembering shapes + colours, tracking object movement, planning spatial movements and navigating environments.
What activities can disrupt VSS processing?
- Finger tapping
- Eye/arm movements
PL (STM) specialises in
storage of speech-based code
Word length effect on word list recall
- Better STM performance for shorter over longer words.
- Implies that it isn't primarily no. of items held which constrains PL capacity
Time-based views of STM capacity
- No inherent structural limitation of PL
- STM capacity constrained by time taken to report items
- As no. of syllables in a word increases, reading speed and correct recall % decrease proportionally
- Weak radiotracer in blood
- Measure blood uptake in brain regions
Neurophysiological PET investigation of spatial + verbal task
- Spatial: significant foci of activation in right hemisphere
- Verbal: significant foci of activation in left hemisphere
- So supported by separate neural areas
Working memory training effectiveness
- Some near-transfer effects (improvement on tasks almost identical to training tasks)
- V few far-transfer effects
- Benefits may be only short-term
Some patients cant repeat >1-2 words/no.s in STM task but can speak normally in convo. Paraphrase instead of repeat. Suggests?
Poor phonological STM, but good semantic STM
Phonological STM disorder patients
- Difficulty learning new words in LTM
- In children, poor vocab, difficulty learning new words
- Knowledge of meaning + function of words/objects
- Supports inferences
Semantic LTM deficit leads to
- Difficulty learning new concepts
- Problems in understanding + producing complex meaningful sentences
What is episodic memory
Links memories from various LTM systems to store a record of a personal event
What is procedural memory
- Learning skills over many trials
- Doesn't require episodic memory of performing procedure
Single dissociation of dyslexic readers have difficulty IDing words compared to control but fine w faces suggests?
- Either word + face recog in separate systems
- Or words more difficult/more recent skill
Double dissociation of dyslexia and prosopagnosia for face/word recog suggests:
Two types of visual LTM, for words + faces
Double dissociation for LTM system, separates what systems?
Environmental sounds v Spoken words
What is pure word deafness?
Can't understand words, understand environmental sounds
What is auditory agnosia?
Can understand spoken words, not environmental sounds
a. Anterograde amnesic patients have poor ? but good ?
b. Phonological STM patients have poor ? but good ?
Double dissociation suggests?
- a. poor episodic memory, good PL STM
- b. poor PL STM, good episodic memory
- STM + episodic memory are different systems (Episodic memory can be supported by other LTM systems)
Double dissociation between Amnesia and Parkinson's/Huntington's suggests
Dissociation between episodic LTM (bad in amnesia) and procedural learning (bad in P's/H's)
Effect of practise by repeated or random trial on reaction time of procedural affected patients:
Generally improve, no improvement for repeated over random.
Location of brain activity for face and word recognition:
- Faces: left + (mostly) right fusiform gyrus
- Words: left fusiform gyrus
What is encoding?
First step in episodic memory creation requires paying attention to events
What are 2 ways to encode info + effectiveness
- Maintenance rehearsal - Inefficient
- Elaborative rehearsal - Efficient
What is maintenance rehearsal
Keep info active in STM by relying on PL (no consideration of meaning)
What is elaborative rehearsal
Encoding meaning of to-be-remembered info
How does elaborative encoding improve digit span
Performance mediated by LTM, not STM. List translated into meaningful info.
Elaborative encoding is best when organising new memories to fir w old. Implications?
- What we encode is affected by our background knowledge, interests, how we organise new info w old
- Therefore people often remember things quite differently
What is the picture superiority effect
- We encode pictorial info better than verbal
- Even imagination of visual format improves encoding over just word
What is the concreteness effect
Words like car, house, remembered better than abstract words e.g. truth, betrayal
What do combined picture superiority effect and concreteness effect support?
- Dual code theory
- Info stored in at least two forms:
- Verbal/linguistic code + Mental image code
What are mneumonic devices?
- Improve memory by improving encoding of info
- E.g. method of loci. Link items in list to route though memory of familiar path
What is consolidation?
Conversion of memories into format resistant to forgetting.
Short term consolidation:
Hippocampus linking info from various LTM systems to form episodic memory
How long does STM consolidation take?
Brain trauma erases memories encoded second/minutes before trauma. What is this, and evidence of what?
Short-term retrograde amnesia - evidence of short term consolidation
Long term consolidation:
Occurs over months/years. Observed in retrograde amnesia - sparing of older memories following ECT
Hypothesis of movement of episodic memories hippocampus to cortex? Accuracy?
- Hippocampus initially (ST consolidation) links all LTM types to store record of episode.
- Over time, memories in LTM linked directly to for episodic memory, moved to cortex.
- Therefore damage to hippocampus doesn't erase old episodic memories.
- Not believed
Multiple memory trace hypothesis?
- Old memories are better encoded within hippocampus bc they've been rehearsed more
- Episodic memories rely on hippocampus always
- Denies LT consolication
Does data support LT memory consolidation by movement of episodic memories to cortex, or MTM hypothesis?
MTM: fMRI shows hippocampus used to retrieve old and new episodic memories.
What is retrieval?
Partially automatic, requires memory cue
What is recall?
Not given memory cue (unlike retrieval)
Korsakoff amnesia: damage, recall v recog, adverse symptom?
- Frontal lesions
- Recall more affected than recognition
- Confabulation (honest lying)
Requires strong retrieval cues
Why does hippocampus need another system to correct itself
Memory associations not always correct, hippocampus cannot correct self. Need to correct to prevent confabulation
- Not strong enough retrieval cue for automatic retrieval
- Need to use frontal system (not just hippocampus)
Role of frontal system in effortful retrieval
- Generates better retrieval cues than hippocampus
- Also monitors and eliminates errors in memory retrieval
- Requires for face recall
- Analogous w central executive in working memory
Retrieval and encoding specificty def.
- Effectiveness of a retrieval cue depends on how well it relates to initial encoding
- (The way we perceive + think abt evens at encoding determines what cues will later elicit episodic memories)
What idea explains state dependent and mood dependent memory?
Retrieval and encoding specificity
What causes childhood amnesia?
- Encoding specificity
- Childhood memories not retrievable as don't have right cue
- Smell is good cue as primitive sense, unchanged in adults.
Practising retrieval during study dramatically improves memory due to encoding specificity
In what 2 general ways do memories fail?
- 1) forgotten as poorly encoded/poor retrieval cue/loss of storage (retroactive interference)
- 2) false memories remembered due to errors in encoding or retrieval
Why is memory distortion at encoding relevant in crime?
What is question wording affecting answers an example of? Who demonstrated this?
- Loftus + Palmer (1974)
- Distortion at retreival
Experiment: participants given list of words to recall, relating to critical lure. Results?
- % false recall can be higher than correct
- High confidence ratings to lures
Does reading support idea of language being learned or instinct?
Does verbal language support idea of language being learned or instinct?
May be instinct
Can brain damage specifically impair language?
Yes, e.g. Broca's aphasia. Suggests language = evolved?
What is the critical period for language learning? e.g.s
Can only learn syntax/sign-language/accent early on in life
Advocates for language instinct often claim language is unique to humans. Why?
Human language seen to be learned differently to way animals learn language - animals have v primitive vocab/syntax only
Argument against critical period for language?
Immigrants (US) show Eng proficiency decreases linearly as age of inquisition increases (no sudden drop-off)
Fact that everyone claps their hands, washes their hair is e.g. of?
Fact that something is universal doesn't make it an instinct
Why doesn't absence of language in other species challenge language instinct hypothesis?
- Human's aren't descendants of chimps/monkeys, so irrelevant that they don't have language.
- 99% of all species extinct, may have been species before us w language
Modern alternative to instinct theory?
- Language is by-product of increased intelligence - result of evolution
- Language is universal because essential to survival - a priority
Language: freq effect
High freq words read quicker than low freq words
Language: regularity effect
Regular words read quicker than irregular
Language: Freq * Regularity effects interaction
Regularity effect only found for low-freq words
Difficulty reading irregular words, fine w non-words + regulars
Difficulty in reading non-words, fine w regular and irregular
What double dissociation is should by surface and phonological dyslexia?
Dissociation between irregular words and nonwords
- Difficulty w nonwords, irregular and regular.
- Better w high imageable than low imageable words
- Often make semantic errors e.g. Pig as elephant
Orthographic knowledge def
Visual knowledge of words + letters
Knowledge of how letters + words sound
Semantic knowledge def
Meaning of words
- Word-level knowledge.
- Can be lexical-orthographic,
- lexical-phonological, lexical-semantic
Sub-word info e.g. individual letters/phonemes, or groups of letters (graphemes) or of phonemes (e.g. syllables)
Group of (written) letters
Group of phonemes
3 routes of language processing:
- Sub-lexical route
- Lexical-phonological route
- Lexical-semantic route
Which routes (Sub-lexical, Lexical-phonological, Lexical-semantic) can regular words be read by?
Which routes (Sub-lexical, Lexical-phonological, Lexical-semantic) can irregular words be read by?
Lexical routes (2+3)
Which routes (Sub-lexical, Lexical-phonological, Lexical-semantic) can rnon-words words be read by?
Sublexical route only
What language processing route is damaged in surface dyslexia?
Damage to lexical routes
What language processing route is damaged in phonological dyslexia?
What language processing route is damaged in deep dyslexia?
All damaged, but can read partially by lexical-semantic route
Why are low-freq irregular words read slower than regular. Why not in high freq?
- High freq words processed quicker within lexical routes so lexical routes finish before sub-lexical routes.
- In low freq words, irregularity causes conflicting pronunciation derived from lexical and sub-lexical routes
What is the effect of visual similarity of written words on reading time?
Similarity hurts identification e.g. crown/crow
What is developmental dyslexia?
- Difficulty learning to read despite normal intelligence + opportunity
- Often due to mild difficulty in phonological processing
- Strong version of linguistic relativity
- Specific language constrains thinking
- Largely rejected
- Weaker version of language specific effects
- Claims language shapes/biases thoughts of speakers
- e.g. easier perception of colour differences if distinguished by language
- Weakest version of linguistic relativity
- Languages shape thoughts (perceptions) of speaker while speaking
- Contrasts w linguistic relativity research (which focuses on impact of lang. on non-linguistic thinking)
How to English v Mandarin talk abt time?
- Eng. front/back
- Man. vertical, up/down
What are relative terms for spatial description?
Specify direction + location relative to viewer
What are intrinsic terms for spatial description?
Specify in terms on object-centred coordinates
What are absolute terms for spatial description?
Based on global reference frame centred on the object (North etc.)
When is Categorical Perception revealed?
When we perceive discrete categories in a continuous range
What is the sharp labelling function of CP?
Absolute answer, characteristic perceived as being solely in 1 category (no doubt/gradient)
What is discontinuous discrimination in CP?
Can't tell difference within a category, but can tell difference at boundary
Why don't our colour perceptions faithfully mirror the physical properties of light?
Our perceived differences of wavelength in different categories are exaggerated, in the same category are minimised.
What does distinction between perception of "pa" and "ba" show?
- Perception of voice onset time is categorical even though stimuli is varying in a continuous way
- Ba to Pa difference is gradient, not distinct sounds
What are two possible explanations for why we show categorical perception in the domain of speech and vision?
- 1) our language impacts our perception of colour + speech sounds
- 2) physiology of the visual and auditory systems is such that we would show CP independent of language (Colour terms are by-product of which appear most salient, phonemes selected are by-product of most salient contrasts)
Animals show similar CP in case of speech. What does this suggest?
CP must be at least partially physiological as animals CP cannot be affected by language
English speakers cannot distinguish some Hindu and Zulu phonemes. What does this suggest?
Language experience impacts on perception of sound
Why doesn't Berinmo participants being able to remember Berinmo focal colours better than english focal colours prove that visual CP is language based?
This experiment is a measure of colour memory not perception
Colours that cross boundary in R visual field identified more quickly than those in LVF, colours that don't cross boundary IDed more slowly in RVF than LVF. ID time same for LVF regardless of crossing or not. What does this show?
- Colours in RVF projected to left hemisphere
- Left hemisphere responsible for language processing
Verbal interference affects russian speaker's ability to distinguish more quickly between light and dark blue shades, but spatial interference does not. What does this suggest?
Visual CP of blue by russian speakers is influenced by verbal capacity.