What are the main components in the original cognitive model (Baddeley & Hitch, 1974)
- ) Phonological Loop
- ) Visuospatial Sketchpad
- ) Central Executive
STM
What are properties of the phonological loop
Phonological Loop: Stores memory traces for few seconds before they fade (7 +- 2)
- Articulatory rehearsal process
- Limited capacity due to articulation (as items increases, point reached when first item faded before latest item is rehearsed)
What are the 4 evidences to support existence of a phonological loop
- ) Phonological similarity effect
- ) Word-length effect
- ) Irrelevant sound effect
- ) Lesion data
What is the phonological similarity effect
Similarity > Meaning to accurate recall
Opposite to LTM - Meaning > Similarity
What is the word-length effect
Syllabus increase; Span declines
What is the irrelevant sound effect. What is the crucial requirement
Recall is impaired b concurrent/subsequent presentation of irrelevant spoken material (speech, music)
Crucial requirement: State of irrelevant stimulus stream must fluctuate
What is lesion data evidence to support phonological loop
Patients with verbal deficit/broca area lesions = no phonological similarity/ word length + they avoid articulation
What is the task typically used in phonological loop
Digit span/ Backwards digit span
What are properties of the visuo-spatial sketchpad. What is the typical task
Corsi blocks
- Limited capacity: 4 +- 1
- Visuo-Spatial has no distinction
Verbal and Spatial WM architecture
Early studies suggests hemispheric and anatomical specialization - recent studies suggest they are shared.
What are properties of the central executive
- Divide/Switch/Focus attention
- Connects working memory and LTM
- Required for working memory task and manipulation of info held in storage components
What task is typically used to assess central executive
Orientation Span Task
What is the orientation span task
- Participants read equation aloud & indicate validity of provided answer.
- 5 Questions: Participants write down words in the order and will only be scored for sets completely recalled in correct order
Why is the orientation span task useful to assess central executive
Requires manipulation of information and storage in working memory
What do direct neuronal recording in non-human primates in a delayed response test show
Fuster & Alexander (1971):
Cells in prefrontal cortex specifically fired in the delay period of a delayed response test (persistent activity)
What is persistent activity of neurons in delayed period: 5 Properties
- Persist through delay period
- Persistence during time epoch when the representative is active (activity dissipates when representation is no longer needed)
- If activity does not persist through retention interval, memory performance is compromised
- Magnitude of activity associated with memory load
- Selective
Evidence for selective of neurons in non-human primates (1)
Specific neurons in DLPFC were SPATIALLY selective - showing delay period persistence for a particular location in visual space
Evidence for selectivity of neurons in non-human primates (2)
PFC neurons selective for:
- Cues
- Delay Period
- Responding
What does persistent activity represent/not represent about past stimulus?
- Represent the maintenance of past stimulus
- Present in anticipation of future stimulus
- Present for maintaining abstract information (rules, associations,etc)
Not visual stimuli. PROCESS of maintaining stimuli
What is recognition performance affected by
Load-effected.
WM load increase; PFC activity increase
i.e.
No. of items increase; RT increase and accuracy decrease
If recognition performance is load-affected, does it tell us whether its maintainance, manipulation, or selection? What is the first study discussed
No.
fMRI: Structure (more PFC) vs Unstructured (less PFC)
EEG studies/Oscillations of working memory
Theta (4-7Hz): Organisation of sequentially ordered WM items
Alpha (8-13Hz): Active inhibition of task-irrelevant information
Gamma (30-200Hz): WM Maintenance
Task for WM and EF
Maintain WM load while performing incongruent responses (Combine WM and EF Task)
Link between WM Load and EF task.
High WM = Longer RT; Greater distraction; Greater processing of irrelevant information (e.g. face FFA)
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W1L1 - fMRI21
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W1L2 - Electrical signals in the brain25
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W2L1 - Face perception, disorders of face recognition, and super-recognisers22
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W2L2 - Neural mechanisms of face perception in humans and non-humans16
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W3L1 - Face processing and emotion22
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W3L2 - Behavioral and Neural Evidence for Numbers37
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W4L1 - Non-human primate studies of the neural basis of number processing21
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W4L2 - Brain imaging and electrophysiological studies of humans with normal and abnormal number capacity21
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W5 - Colour27
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W6 - Reality26
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W7 - EF60
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W8 - Performance Monitoring36
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W9 - Memory49
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W10 - Emotions43
