W9 - Memory Flashcards
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)
How is WM load linked with drug use and cravings.
Processes overlap. Inhibitory control may be affected by simultaneous working memory load such as a craving.
(Craving about cocaine = activation of cortical network)
What are the results of IC and WM and DLPFC
WM increase; Cocaine users IC decrease
WM increase; DLPFC predicted better performance
What are the consequences of drug-related stimuli in response inhibition and working memory
More difficult to ignore task irrelevant (drug-related) material (Rumination and Rumination load on verbal working memory)
Decreasing accuracy and increasing response time
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
Is WM related to EF
Yes. Predict one another.
Clinical patients often show impairments in both domains
What is the hypothesis relating WM and EF
WM needed for goal-maintenance required for top-down/executive control
WM and other skills
Improvement in performance = Change in functional activity
- Correlated with general fluid intelligence
- Reading comprehension
- Language
- Non-verbal problems solving
Working memory and training: Neural mechanism
Correlation between IQ, WM, and structural/functional PFC performance.
Does training WM improve performance?
Yes. Other skills improvement via. WM
What are the 2 principles relating WM and training
Training WM Task:
- ) Increase WM Capacity (physiological change); or
- ) Increase efficiency of using working memory capacity (via. strategy use such as chunking)
Principle 1: Increase WM capacity. What should happen
- Should induce brain signatures observed in high-capacity individuals.
- Benefits and pattern changes observed independently of specific task
What does the N-back task measure/not measure
Measures WM performance, not capacity
N-back task training and cortical results
Training:
1) Post > Pre WM Training fMRI
2) Regions where brain activity correlated with increased WM capacity
What is the problem with the results inferred from N-back task training
They did not run an interaction test - did not examine interaction if (Post > Pre WM Training) is correlated with (Regions where brain activity correlated with increase WM capacity)
How does training increase WM, and…
Increases efficiency, and individual differences in dopamine affect training benefits
Does WM improve IQ
Has been evidence
How does WM improve IQ
Improve efficiency:
- Greater chunking
- Automatisiation of basic processes = Task practice lowers distractors
3 Criticisms of WM & Training Benefits
1.) Cost-Benefit Analysis
Financial+Time Cost > Benefits
2.) Genersaibility
No evidence of generalisation to other skills/tasks
3.) Sustainability
Weak/mixed evidence after cessation of training
WM training on ADHD children: results
Raters: Lower symptoms
Independent Raters: No Change
WM Performance and Parental rating increase; Lab test & academic performance no change
Study: Neuroracer Descriptive Statistics
N = 47, 67 years old
What are the results presented in neuroracer study
- WM & Control Task increase “Behaviour”
- Midline frontal theta power & theta coherence increase “EEG”
Criticism of Neuroracer’s publication
- Most comparision are not significant (multiple comparision not corrected)
- Competing financial interest - founder of company
- Excluded many participants
Academic outcomes of Training
Big study no outcomes
Far Transfer of Training
Small-moderate effect (does not occur) - Might be placebo effect
Neural pattern reflect domain specific ability (best way to acquire new info is to train)
