1. Intro to Cognitive Psy. = study of how brain processes information
Cognitive processes - main stages of processing: INPUT → perception (analyses of content) → learning &
memory storage (making a record) → retrieval → thinking (rearrangement of old info)
- stages are continuous, overlap
- approaches to cognitive psychology:
Experimental psychology = scientific testing of psychological processes
- behaviourism = investigates only externally observed events, rejects mental
processes (not scientific) → slowed down cognitive psy.
- Gestalt = integration of elements into whole figure (more than the sum), observer
contributes to perceptual input
- schema theory (Barlett) = pattern, assists w/ interpretation of input, perception of
input is distorted to fit schema (perception is unique → lies in the brain of observer)
- top-down processing ( = schema-driven/ conceptually driven); uses schema for
interpretation, of complex stimuli (vs.) bottom-up processing (= stimulus-driven/
data-driven); determined by nature of stimulus → happen at same time
Computer modeling = simulation of processing, for testing feasibility of a model; 1950s
- feature detectors = system of convergent wiring that responds to specific features in
a pattern; like 'mini-schemas' that identify shapes and patterns; feature detector cells
- limited-capacity processor model (like a PC!) = selective attention to avoid overload
Cognitive neuroscience & = brain function, structure + cognition, activities; PET (radioactive), MRI (magnetic)
Neuropsychology = brain mechanisms of cognitions (brain damage)
- cortex: lobes are interconnected, but also modular (experts, specific)
- hemispheres: le (language, speech) vs. right (non-verbal input, pattern perception)
- frontal lobes: [output] motor region; production of speech (Broca's area); central
executive system (conscious decisions…) vs.
- [input] occipital (visual percep.), parietal (somatic sensory cortex: pain; short-term
memory) and temporal (encoding & retrieval, auditory percep: Wernicke's area)
- double dissociation = independence of 2 functions (e.g. LTM and STM), if one is
affected, the other is not!
- Hebb's theory: info is stored in a cell assembly (= single functional network,
represents a pattern of input), formed w/ release of neurotransmitters into synapse
(memory and thoughts become associated w/ one another) → LTP
Automatic processing = unconscious, don't require attention, unlimited capacity, fast, involuntary, habit;
Stroop test; vs. controlled processing
- explains recognizing familiar face, but not context of meeting the face
- explains absentmindedness (action slips)
- must be controlled by supervisory attention system
- consciousness (frontal lobe) takes up charge: automatic processes lack flexibility
- consciousness awareness: a mystery, but linked to: conscious amnesia, blindsight
(unconscious sight), autism (mostly driven by automatic proc.)
Integration of approaches - mins, brains and PCs;
- main areas in cognitive psych.: perception, attention, memory, thinking, language
2. Perception = subjective experience of cognitive info a er cognitive processing of it
Visual perception - template matching theory (as in schema) = internal templates are stored
representations enabling object recognition, but first encode info!
- Gestalt approach: segregate figure and background (reversible figures!); laws of
perceptual organization = principles for organizing stimuli (proximity, similarity)
- feature-extraction theories = template-matching, but w/ features of the object, not it
as a whole; Pandemonium = demons shout feature found in input, sum up to whole
(1) Marr's computational theory: stages of processing until internal representation is
, formed; primal sketch (computation of edges and other details) → 2,5 D sketch
(groups features, forms surface, viewer's point of view) → 3D sketch (independent of
viewer, achieved perceptual constancy) → compare to stored representations
(2) Biederman's recognition-by-components approach: the identification of the object
is through identification of geons (= 3D features) of that object (what if it changes?)
- Parallel distributed processing (PDP) models = stimuli is represented not by
neurons, but by network of neurons (pattern of activation); matched w/ template
(stored knowledge = info in perceiver, top-down); allows for adaptation and learning
new info
- visual illusions (when perception is distorted): a continuum, influence of physics?
Sensory system? cognitive processes (top-down)?; Müller-Lyer (interpret w/
knowledge of 3D, rescaling, size constancy); strong influence of what we know
- sensation (raw bottom-up input) → attention (filter out info) → knowledge (distorts) →
perception (conscious end result of processing of input
- Kant: numena = world as it is vs. phenomena = numena perceived
- sensory conspicuity = how easily object is detected, depends on its features,
contrast w/ background; bottom-up
- attention conspicuity = individual → to consciously "see" object (overemphasis on
prior knowledge can lead to accidents LBFS)
- visual search = scanning through distractors for seeing target (filters attention)
- constructivist theory: perception for recognition (sensory info is incomplete: bad
quality + info filtered out); interaction btw bottom-up & top-down (create perceptual
hypotheses, test against input) determines perception
- evidence for constructivism: visual masking (changing stimulus interrupts
processing of target, i.e. re-entrant processing = flow of info btw brain regions,
bidirectional! → top-down, bottom-up)
- Gibsonian theory: perception for action (we see affordances); direct perception in
real world (no need for top-down processing, interact w/ environment around)
- Gibsonian dorsal (parietal: WHERE, faster, short-term, viewer-centered, for action) &
constructivist ventral (temporal: WHAT, conscious, object-centered, detail, for
recognition) streams (both from occipital to frontal lobes)
- interaction of the streams: phenomenological experience (conscious experience of
the world, we do not see it blur): use environment as external memory (ventral stream
generates stored representations of it), but dorsal warns ventral for eventual changes
- the streams are more like currents in a lake (a network, + complex)
- we perceive things not as they are, but as we are
3. Attention = prioritization of information processing; focalization of consciousness; withdrawal
- to capture attention: source takes priority over (interrupt ongoing processing)
- maintains info available in short-term working memory, limited amount
what for - selection for perception: attention for encoding and interpreting sensory info
- selection for action: attention for planning, controlling and executing responses
- involves 'what' and 'where' pathways → 2 info are binded correctly: binding problem
- endogenous: intended, controlled, executive control, top-down, conscious
- exogenous: stimulus-driven, bottom-up, automatic processing, uncontrolled (Stroop
effect, well-learned response), unexpected relevant chages, interrupts endogenous
- slips of action: when a step in automatic action is skipped or misdirected
- involves multiple brain areas, different for different tasks
the limit - psychological refractory period (PRP):delay in RT to second stimuli when it comes
early enough to overlap with processing of the first (demonstrates bottleneck: limit
when parallel processing becomes serial)
- shadowing: repeating back what is heard in dichotic listening, ignore other message
- Cherry: shadowing task; bottleneck is located btw. perceptual processing (changes
could be noticed) and semantic processing (not processed at all)