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Cognitive Processes (PSYU2246) - Coggle Diagram
Cognitive Processes (PSYU2246)
Approaches to human cognition
Study of cognition
Definition
Aims to understand the workings of the human mind by studying human behaviour, often using experimental methods and also computational modelling, neuroscience and neuropsychological data
Information processing models
A general info processing model
Most cognitive behaviour involves more than just one cognitive process
cognitive psychologists take the info from perception processing and analyse the higher lebvel of cognitiion processing
Image on page 11 of week 1 powerpoints
Information processing approach
Major goal is to specify the processes and structures involved in cognition
Scientists see the response made to the problem (the action taken) and make an inference of how the response is make by making inferences to cognitive behaviour
Types of processing
parallel vs serial
Discrete serial processes
one process takes place after the other is completed (turn ignition -> step on accelerator) second process doesn't occur until the one one is completed
Cascaded processes
more serial, but overlapping (turn on indicator, turn wheel to change lane
Parallel processes
2 processes happen in parallel (e.g. talking and driving)
Bottom-up vs top-down
Bottom-up
External stimulus causes internal cognitive processes to occur, producing the desired response (stimulus driven by information processing). the stimulus is the bottom up info that makes use of what's inside your head to make a response
Top-down
Processing influenced by the individual's expecatations and knowledge
paris in the (the) spring example: Top down expectation is where you're familiar with the phrase but don't process the phrase word by word - is not completely stimulus driven
Not necessarily about the error but rather it's due to the ambiguity of the stimuli and it combining with top down expectation
(The) (Cat) example: if it were purely bottom up processing, you would always interpret "A" in the same way, expectation of the word helps interpret it in a different way
Moses and the ark example: the knowledge of the bible and the semantic expectations at play initially confuses the individual into thinking the sentence makes sense - Moses and Noah ae semantically similar as well
Approaches to study of cognition
Cognitive neuropsychology
Key assumptions
Anatomical modularity
That each module is located in a specific brain region
Functional modularity
Cognitive system consists of neumerous independent priocessing unit
Modules exhibit domain specificity (that they respond only to one class of stimuli)
eg in reading, a module for reading familiar words and a module for unfamiliar letter strings
These assumptions may not be met because brain damage may be diffuse (alzheimer's) or the cognitive process in question recruits many brain areas (Reading, memory)
Concerned with the patterns of cognitive performance (both intact and impaired) shown by brain damaged patients
Makes use of data from them to make inferences on normal cognition
Study of brain damaged patients
The attempt to understand human cognition by studying brain damaged patients (alzheimer's, acquired dyslexia)
Cognitive neuroscience
Techniques include
Position emission tomography (PET)
Functional magnetic resonance imaging (fMRI)
Blood oxygen-level-dependant (BOLD) contrast
Measures changes in blood flow (haemodynamic activity) during cognitive activity
Active brain regions have a higher ratio of oxygenated to deoxygenated haemoglobin (blood), which have different magnetic property
Strong magnetic field: aligns most water protons
Radio frequences: disrupt alignment
Protons gradually realign based on: 1) type of tissue, 2) spatial location, 3) Deoxygenated blood
Signal is reconstructed to form activation maps
fMRI provides a non-invasive, indirect measure of brain activity
Spatial resolution is high (within milimetres), but temporal resolution is poor (due to sluggish blood flow)
Magneto-encephalography (MEG)
Measures magnetic field that changes with electrical activity
uses a superconducting quantum interference device (SQUID)
Provides high temporal resolution and moderate spatial resolution
not prone to some of the artifacts that affect scalp EEGs (since the skull is transparent to magnetic fields)
Limitations
expensive to build a magnetically shielded room
Expensive to keep the SQUID cool (liquid helium is used)
Requires the participant to maintain a potentially uncomfortable position for long durations
The technology and analysis are relatively new and complicated
Event-related potentials (ERPs)
Measures electircal activity of brain at the skull
EEG non-invasively meaures electrical activity in the brian during cognitive activity
Electrodes are placed on the scalp; ERPs are EEG recorded in response to an event, measured when doing a particular cognitive presented with stimulus
Limitations
requires many trials due to weak signal
measures a subtle signal change at the level of the scalp (vs the structure generating the activity)
limited spatial resolution, but high temporal resolution
Skull and brain tissue distort electrical fields
Largely blind to subcortical activity
Difficult to determine source of neural activity (where)
Transcranial magnetic stimulation (TMS)
rTMS: repetitive TMS, the pulse is applied repeatedly
creates a 'temporary lesion' which temporarily mimics the effects of brain damage and inhibits a particular part of the brain
the pulse is applied repeatedly and experimentally cfreates a reversible brain damage
a lot of exclusion criteria in choosing research participants
A very brief (less than 1 ms) magnetic pulse is applied by a coil, which creates a short lived magnetic field that is an electical stimulation to the brain
Single-unit recordings
Key terms for evaluating neuroscience methods
Spatial resolution
The accuracy with which one can measure where an event occurs in the brain (could be loose or precise)
Invasiveness
Refers to whether the equipment is located internally or externally
Ethical implications
Temporal resolution
The accuracy with which one can measure when an event occurs in the brain
Study of human brain and cognition
The attempt to use information about behaviour and the brain to understand human cognition
Computational cognitive psychology
Computational models
Computational modelling
simulation
compares the model's behaviour to human behaviour
Programming computers to model (mimic) some aspects of human cognitive function
word recognition models (Coltheart et al, 2001), Dual-route cascaded (DRC) model of reading aloud
Computational modelling requires researchers to make their assumptions explicit
e.g. DRC model: letters in a real word are processed in parallel while letters in a non word are mapped into sounds serially letter by letter
The attempt to use computational models to further understanding of human cognition
used to develop a computer model that can be implemented, such as suto translate or suto speech recognition
Cognitive psychology
Experimental method example: the phonological similarity effect
Tutorial 1
What is the nature of the code used in verbal short term memory?
Immediate recall task
DV is the number of letters recalled in correct position
2 x 2 factorial design: 2 IVs (each with 2 levels)
Phonological similarity - similar, dissimilar (2 levels)
Presentation mode - visual spoken (2 levels)
Results
Phonologically dissimilar list is recalled better, irrespective of presentation mode
Interpretation
Verbal short term memory uses a speech based code
Visually presented letters are re-coded into a speech based format
Phonological similarity hurts performance in a similar way in both visual and spoken recall
The attempt to uncover the nature of human cognition by observing people's behaviour
Typically uses experimental method to test research hypothesis
IV: The factor or dimension manipulated/varied by the experimenter
Each IV has at least 2 levels (conditions)
Factorial design combines more than one IV
e.g. drug dosage (drug A, Drug b, placebo - 3 levels) x Sex (2 levels): 3x2 factorial design
DV: What is measured
Different approaches have different strengths and weaknesses reflecting the measures used
All methods involve making inferences about underlying cognitive processes from observable pattern of data - how the interpret results are not straightforward
e.g. the so-called visual word form area (VWFA) shows greater BOLD signal to a word than a striong of consonnats, so is VWFA a 'word detector area?
This occurs during passive viewing but the opposite is found during a one back task, BOLD signal does not correspond to the activation of a word detector
Working memory
Baddeley's (2001) working memory model
Other components of Baddleley's working memory model
Episodic buffer
Central executive
Norman & Shalice's SAS (supervisory attentional system)
Executive functions
Visuo-spatial sketchpad
Phonological Loop
What is phonological loop for?
Digit span across languages
Findings/evidence of phonological loop
Word length effect
Memory span is reduced for longer words
Phonological similarity effect
Practical 1
Effects of articulatory suppression
Baddeley (1966)
Immediate serial recall of verbal material is reduced for items that sound similar
Conrad (1964)
The system
Phonological loop system is based on verbal/speech based memory
2 structures: Phonological store and Articulatory control process
Passive phonological store
Articulatory control process
Baddeley & Hitch's (1974) model
Episodic buffer was proposed later in 2001 to account for ata that could not be explained bu the original model
All components of the system are thought to be limited in capacity and relatively independant of each other
The central executive resembles attention
a control system that co-ordinates the peripheral storage ('slave') systems
if two tasks usees the same component, they can't be performed successfully together
If two taks use different components, they should be able to be performed similarity togethr or separately
His working memory system replaced the concept of 'short-term store' with 'working memory'
Major components of his system
Central executive
Uses slave systems
Modality free, not tied to 1 sensory modality
Deals with any cognitively demanding task
Resembles attention
Phonological loop (inner voice)
holds info in a speech-based form
Episodic buffer
Holds and integrates diverse information from different store systems
Visuo-spatial sketchpad (inner eye)
specialised for spatial and/or visual coding
Working memory vs short term memory
Memory: architecture and processes
Processes
The activities occurring within the memory system
The multistore memory model emphasizes on the 3 structures
Sensory stores
Holds information in its original sensory modality (visual, auditory)
Short term memory (STM) store
Storage is fragile
very limited capacity
Long term memory store (LTM)
Essentially unlimited capacity
Holds information over long periods of time
Criticisms of the original multistore model
It overemphasised the structural aspects of memory
Emphasis on processes (episodic memory), activities that occur in the model
STM is not a gateway to LTM
The memory systems are interconnected
STM tasks make use of knowledge in LTM, such as chunking (chunking info into meaningful units, making use of knowledge in LTM to improve performance in STM tasks)
Rehearsal may not be as crucial to learning
Maintenance (rote) rehearsal does not result in durable memory
Craik & Watkins (1973)
Amount of rehearsal not proportionate to recall
Impairment of STM does not necessarily lead to impairment of LTM
Patient KF
Background: m/28; left parietal-occipital fracture in motorcycle accident 11 years before, Verbal IQ (includes memory span) low (79), performance IQ high (113)
The main deficit: inability to repeat verbal material
digit/letter/word span of 1 (small STM span)
recognition memory by pointing also poor (i.e. not motor speech function deficit)
Yet, his paired associate learning (of associated words, e.g. baby-cry) with 24 hour delay was normal
therefore impaired STM but intact LTM
Warrington & Shalice (1969)
model implies that it's a one direction occurrence
STM and LTM store are not unitary
Each store does not operate in a single uniform fashion, but has subcomponents
STAM is replaced by working memory, LTM replaced by episodic memory and semantic memory
Architecture (structure)
The way in which the memory system is organised
Attention
Focused auditory attention
Selectivity
bottlenecks models of attention
Treisman's attenuation model
Deutsch & Deutsch's late selection model
Early vs late selection
Flexible bottelneck view
Broadbent's filter model
studies of auditory selective attention
Dichotic listening
Findings by Cherry, Moray
The cocktail party phenomenon
Divided attention
Control and automaticity
Charactersitics of automaticity
Multitasking
Practice
Meaning of attention
Selectivity
Control
Alertness
Visual Attention & Face and Object recognition
Visual attention
What can attention select?
What is the relationship between eye movements and attention
Visual search: What can it tell us about the nature of attention
What is attention and what does it do?
How and why do we shift attention: Exogenous and Endogenous attention
Face and Object recognition
Is face recognition different to object recognition
Face processing and visual expertise
Theories of object recognition: How are we able to recognise objects from different views?
Insights into face processing from cases where skilled face processing fails to develop
What is object recognition important and interesting?
Episodic memory
Memory processes
Encoding processes
Spread of processing (Elaboration)
Application: Levels of processing and note-taking (longhand vs laptop)
Creik & Lockhart's levels of processing framework
Practical 3
Limitation: Levels of processing with doors vs words
Retrieval processes
Varieties of memory tests
cued recall
recgonition
recall
implicit memory tests
Encoding specificity principle (Tulving)
Recognition failure of recallable words
Tulving & Thompson, 1973)
Not all tests are consisten witht he encoding speicificity princple
Environmental context (Godden & Baddeley)
recall vs recognition
Implicit memory tests
Testing indirect retrieval
Graf. Shimamura & Squire (1984)
Criticisms of the original multistore model
Amnesia
Symptoms
What's impaired in amnesia?
Schacter, Church & Bolton (1995)
Huppert & Piercy (1976)
Binding of item and c ontext: familiairty and recollection