W9 - Memory Flashcards
(43 cards)
What are the main components in the original cognitive model (Baddeley and Hitch, 1974)
STM
- ) Phonological Loop
- ) Visuospatial Sketchpad
- ) Central Executive
What are 3 properties of the phonological loop
Phonological Loop
- Hold memory traces for few seconds before they fade (7 +- 2)
- Articulatory rehearsal process, like subvocal speech
- Limited capacity because articulation occurs in real time
- (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
What is the task typically used in phonological loop and outcome factors
- Digit span task
- Examine how much load size
- Backwards digit span
- Central executive manipulation
What is the phonological similarity effect. Contrast this with LTM
Accurate recall:
- Similarity of sound is more important than meaning of sound
- vs LTM, where Meaning > Similarity
What is the word-length effect
- Span declines as word length increases from one to five syllabus
What is the irrelevant sound effect. What is the crucial requirement
- Impaired recall due to concurrent or subsequent presentation of irrelevant spoken material
- Includes speech, music
Crucial requirement:
- Fluctuation in state of irrelevant stimulus stream
What is lesion data evidence to support phonological loop
Patients with verbal deficit and broca area lesions in absense of an articulation deficit show:
- No phonological similarity effect
- No word length effect
- Appear to avoid articulation
What are properties of the visuo-spatial sketchpad.
What is the typical task?
What does the visuos-spatial sketchpad account for?
Task: Corsi blocks
- Limited capacity (4 +- 1 objects)
- Capaciy to hold and manipulate visuospatial representations
- Accounts for change blindness
- No distinction between vision and spatial (How do we imagine vision without a space?)
Verbal and Spatial WM architecture
Shared hemispheric and neuroanatomical archiecture for both verbal and spatial WM.
No hemispheric specialisation
What are properties of the central executive. What is the task?
Concept of the Homonculus:
- Divide, switch, focus attention
- Connects working memory and LTM
- Required for WM tasks that require manipulation of information held in storage
Tasks
- Orientation Span Task
- Backward digit span
Explain the orientation span task. Why is it used?
Orientation Span Task
- Reads the equation aloud as soon as it appears
- Indicate whether provided answer was correct and read the word at the end aloud
- Do an operation (phonological/visuo-spatial)
- Write down the five words in correct order
- OSPAN score = Sum of recalled words for sets recalled in perfect order
Why?
- Requires manipulation of information and storage in working memory
When do neurons fire in a WM task?
Cells in PFC specifically fired in the delay period of a delayed response test
Spatially selective DLPFC neurons in non-human primates show what pattern of activity
Persistent and location specific activity for a particular location in visual space during the delay period of a WM task
Persistent activity of PFC neurons in delayed period:
When does it persist (2 Things)
What happens if it does not?
When does PFC persist?
- Persist during delay period
- Persist during time epoch when representative is active
- Activity dissipates when representation is no longer needed
- If activity does not persist through retention interval, memory performance is compromised
Persistent activity of PFC neurons in delayed period:
Two more properties (2 things)
Properties:
- Magnitude of persistent activity commensurate or correlated with memory load
- Selective
- Spatially selective (Specific visual space)
- Subsequently identified PFC neurons selective for cues, delay, response
Does persistent activity represent maintainance of past stimulus?
What has it shown to represent?
And what does it suggest?
Persistent PFC activity for
- Visual stimuli in absense of WM demands
- Maintainance
- Anticipation of future stimulus
- Representing or Maintaining abstract information
- e.g. rules, associations, told to maintain
(a) Maintainance; (b) Manipuation; (c) Selection
Not represent
- Maintenance of physical stimulus presentation
Delay is Process of maintainance, not stimulus itself
Describe the Sternberg. What did the Sternberg Task results reveal?
Sternberg
- Hold some items before a delay
- Ask which items come before the item flashed
Results
- As number of items or WM load increases
- Accuracy decrease
- Reaction time increase
- PFC activity increase
- But we don’t know whether it’s maintainance, selection, or manipulation
How have people tried to tease apart maintainance, selection, or manipulation? What are the results
Sternberg
- Number of items is the case, but the structure is different
Results
- Structural items had more PFC activity than unstructured items
- Mean Span (Structured > Unstructured)
- Suggest configuration is represented by 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
TAG
What is the task combining WM and EF. What are the results (And implications)
Task requiring maintance of WM load while performing congruent or incongruent responses (EF Task).
Results
- Longer RT for high WM load
- PFC activity greater for high WM load
- Greater processing in face-processing areas in high WM load
- Greater distraction and obligatory processing of irrelevant information (Faces)
- WM influence can be examined in level of FFA activity (Quantify)
Response inhibition with a WM load in drug-dependent and depressed patients.
Why?
- Inhibitory control affected by simultaneous working memory load of a craving
- Cocaine
- Depression/Anxiety
- Eating Disorders
- Thoughts are subvocally produced and rehearsed, loading on phonological loop capacity (Verbal memory load)
When there is chocolate craving, what is impaired
Significant impairment in visuospatial WM
When there is cigarette craving, what is impaired
- Significant impiarment in verbal WM that worsened with longer periods of abstinence
- Phonological loop
