working memory 2

Question 1

STM capacity

Answer 1

Miller (1956) - magical number 7

memorise series of letters in a sequence, average = 7 +/- 2

Question 2

2 ways to boost STM capacity

Answer 2

active rehearsal

chunking

Question 3

WM capacity

Answer 3

Cowan’s (2001; 2010) magical number 4

only representations in focus of attention (centre of network for spreading activation) are available to conscious awareness

average capacity limit of adults focus of attention = 4 +/- 1

Question 4

set-size effect

Answer 4

larger set = worse performance when recalling strings of letters

later items in the set interfere with the earlier ones - harder to hold into

in both simple and complex span tasks

Question 5

limits of working memory (3 - list)

Answer 5

decay
interference
limited resource

Question 6

WM decay

Answer 6

rapid decay with time
Thorndike’s law of disuse

time-based decay = representations get weaker with time (as a linear function)

first presented unit is strongest as it has had the longest time to be rehearsed over and over

primacy and recency effects seen because of this

Question 7

does time cause WM decay

Answer 7

REMEMBER: time passing doesn’t cause decay, it is correlated with processes that cause forgetting

• processes cause forgetting and these are associated with time

Question 8

WM decay - restoration mechanisms (2)

Answer 8

rehearsal - subvocal repetition of memoranda to maintain them

refreshing - think of memoranda to keep memory traces active

Question 9

WM interference

Answer 9

mutual interference between representations limits WM

seen in set size effect - more units means they overlap and compete with each other

Question 10

WM transience (2)

Answer 10

proactive interference = old impairs new(remember old)
retroactive interference = new impairs old (remember new)

Question 11

3 types of WM interference

Answer 11

confusion

• present array of items verbally or visually
• need to remember position of items
• confusion when you get the position of an item wrong

superposition

• items that seem similar but are dissimilar in terms of positioning
• try to determine positioning of item
• less similar = worse performance

overwriting

• more similar = worse performance
• e.g. cat, bat, mat = easily confused

Question 12

WM limited resource

Answer 12

capacity determined by limited quantity of resource that enables holding representations available

Question 13

what is a resource

Answer 13

resource = limited quantity that enables cognitive function/process; probability of success increases the larger amount of resource assigned to it

• more resource given to an item = remembered better

Question 14

2 resource models of WM

Answer 14

slot models

*egg-carton metaphor
* resources distributed in discrete units (defining the number of items you can store)
* quality of retained representations is high but not perfect
* each item gets equal share of the resource

flexible resource models

• resources are distribute flexibly, this allows for
• small number of high quality; or
• high number of low quality

Question 15

2 ways WM resource can be allocated

Answer 15

discrete = slot model = allocation to limited number of items with no info stored about additional items

continuous = flexible resource model = equal spread of resource among all items, fewer resource per item in larger arrays

Question 16

which hypothesis for WM capacity is best

Answer 16

none can explain all findings:

set size effect + complexity of items
set size effect when delay = 0s
domain specificity
cross-domain set-size effect
heterogeneity benefit

Question 17

variation in WM capacity - who has greater capacity (4)

Answer 17

older children > younger children
young adults > older adults
healthy > frontal lobe damage
some people > others of same age

Question 18

importance of studying variation in WM capacity

Answer 18

correlates with complex cog activities

predictive of things

Question 19

correlations of WM with complex cognitive activities (3)

Answer 19

reading comprehension
reasoning
problem solving

Question 20

what WM can predict (2)

Answer 20

cognitive development
individual differences in intellectual ability

Question 21

2 tasks for measuring WM performance and reasoning

Answer 21

WM task:

• complex span task - storage and processing

reasoning task:

• e.g. non-verbal reasoning, finishing a pattern by figuring out the rule

Question 22

proposed explanations for individual differences in WM (2)

Answer 22

executive attention hypothesis
binding hypothesis

Question 23

executive attention hypothesis - 2 systems

Answer 23

Shipstead et al (2016)

attention control = executive attention

2 systems:
1 = quick and easy access to all info you know
2 = effortful, controlled processing – attention control system

Question 24

executive attention in WM and reasoning tasks

Answer 24

single top-down executive attention system underlies WM and reasoning task performance:

EA –> maintenance or disengagement –> task performance

Question 25

executive attention in a WM task

Answer 25

complex span task

maintenance –> of relevant info (to store the letters) and append to new info on the list

disengage –> from and suppress outdated info (equations) from previous trials

this is the ability to be selective of what info to remember or not

Question 26

executive attention in a reasoning task

Answer 26

disengage –> from outdated rules/hypotheses between trials to prevent returning to them - new trials have new rules to determine

maintain –> info about the problem, allow systematic hypothesis testing

Question 27

executive attention hypothesis - summarised

Answer 27

WM capacity and reasoning are linked - both arise from limited executive attention

better executive attention = better performance in WM, reasoning, and other similar tasks

Question 28

issue with executive attention hypothesis

Answer 28

executive attention tasks don’t correlate well - difficult to directly test hypothesis

e.g. doing one task doesn’t mean you do better in another task of EA - Stroop task and flanker task don’t correlate with each other but both require EA

Question 29

binding hypothesis for variation in WM

Answer 29

binding hypothesis = system for rapid formation of temporary bindings underlies both WM and reasoning task performance

individual differences due to differences in number of potential bindings

more bindings = more WM capacity

WM –> bound by construction and manipulation of representations and novel structures –> reasoning

Question 30

binding hypothesis in WM task

Answer 30

complex span task

each letter is bound to its position in the list to be remembered

Question 31

binding hypothesis in non-verbal reasoning task

Answer 31

objects are bound to semantic space

e.g. blue square and purple circle are bound by colour and shape into a grid (array) - sort by shape and by colour to find missing shape

this is more complex rules/structures than with WM task

Question 32

binding hypothesis - summary

Answer 32

bindings = temporary links of content representations to places in a mental coordinate system

WM capacity limit = number of bindings maintained at any one time (varies between people) - arises from interference between bindings

less interference = build more complex structural representations - therefore do better in WM and reasoning tasks

Question 33

issue with binding hypothesis

Answer 33

bindings may be built and maintained with help of executive attention

difficult to directly test hypothesis against executive attention hypothesis

both hypotheses are too entangled and interlinked

therefore need more research into it