Working Memory Flashcards
INTELLIGENCE
- fluid intelligence/reasoning = ability to find/manipulate info in memory & deploy attention
PROBLEM SOLVING
- depends critically on ability to deploy WM & therefore attention
- aka. breaking complex task down into separately attended parts
DOUBLE DISSOCIATION BETWEEN STM & LTM
- clear evidence for this
- double dissociation logic = if 2 functions depend on overlapping brain regions -> lesion to 1 brain region will tend to affect both functions
- BUT if they’re non-overlapping -> 2 functions = free to vary independently
HM (1954)
- bilateral removal of temporal lobe
- concluded a dedicated memory system in medial temporal lobe
- severe amnesia (inability to form new LTM for events/facts)
- preserved STM
- preserved procedural memory
KF (1969)
- identified w/lesion to perisylvian cortex which reduced digit span (STM) BUT preserved LTM
- double dissociation between LTM/STM w/HM
- strangest neuropsychological evidence for 2 functions being dissociable
BADDELEY & HITCH (1974)
- working memory model
- key distinction between:
1) storage (buffers) in visuospatial sketchpad/phonological loop
2) executive functions (ie. coordination of resources/attentional control/stored info manipulation) in central executive - based on evidence wealth for separability of dif functions at beh/neural lvls
WORKING MEMORY DISTINCTIONS
- to make distinction between storage/executive processes in WM clear it’s worth considering what makes us human in terms of our WM ability
- STM storage = trivial; monkeys are sometimes better at this than us
SHORT TERM MEMORY
- NOT working memory
- simply requires storage of info over short time period
- WM = ability to do something w/info; much more complex
- turns out that its the ability to do something w/info in WM that underlies intelligence
GENERAL INTELLIGENCE: SPEARMAN’S ‘G’ FACTOR
- 1904; Spearman published paper examining correlations in kids between dif disparate measures:
1) academic ability (teacher ratings/exam performance)
2) sensory discrimination
RESULTS - correlations = all positive
- correlation between sensory ability/academic ability = almost perfect
- factor analysis revealed underlying factor common to performance of many dif task kinds aka. ‘g’ factor aka. general intelligence
SPEARMAN’S G FACTOR: ADAPTATION
- adapted into 2 underlying factors later:
1) GF (fluid intelligence) - reasoning/problem solving
2) GC (crystallised intelligence) - general knowledge
KYOLLEN & CHRISTAL (1990)
- asked “what underlies our ability to perform reasoning tasks of the kind measured by GF?”
- gave pps dif processes tests (ie. WM/general knowledge/processing speed)
RESULTS - found v high correlations between reasoning ability (fluid intelligence) & WM BUT not other processes
KYOLLEN & CHRISTAL (1990): TASK EXAMPLES
1) pps required to judge sentences on logical consistence (ie. all swans are white; jane is white; so jane is a swan)
2) had to identify odd one out from alphabetical letter clusters
3) ABC numerical assignment/digit span task
KYOLLEN & CHRISTAL (1990): INDIVIDUAL DIFFERENCES
- suggested close correspondence between WM & intelligence; correlation = so high they suggested intelligence = nothing more than WM
- other functions (ie. general knowledge) didn’t correlate highly at all
- important to distinguish between fluid/crystallised intelligence
- WM correlates w/fluid NOT crystallised intelligence
KYOLLEN & CHRISTAL (1990): ABC NUMERICAL ASSIGMNET EVALUATION
- issues w/tests = don’t distinguish between storage (STM) & executive processes (WM)
- performance depends on combination of these processes
KANE & EAGLE (2002): PROCEDURE
- used tasks involving working aspect of WM or not
- Q = if complex span task would correlate ^ strongly w/tests of fluid intelligence
COMPLEX SPAN TASK - pps had to solve equation & say a word out loud then recall words at the end
- requires working aspect of WM involving retention/manipulation & info processing
SIMPLE SPAN TASKS - pps merely had to say each word out loud then recall them at end
- requires STM retention; no manipulation/processing of maintained info
KANE & EAGLE (2002): TESTS
RAVEN’S MATRICES
- test of general/fluid intelligence
- pps see pattern groups; must find pattern that fits into space
STRUCTURAL EQUATION MODEL
- measures relationships between variables
KANE & EAGLE (2002): RESULTS
- structural equation model identified 3 factors underlying performance of tasks aka. 3 independent cognitive processes differentially engaged by tasks: WM/STM/processing speed
- examined extent to which factors correlated w/measure of fluid/general intelligence (GF)
- correlation between WM/GF = almost perfect
- BUT correlation between STM/GF = negative
- speed/GF = low correlation
- could argue they’re ^ difficult tasks BUT came up w/^ difficult STM task versions w/longer lists
- aka. performance matched across dif task types still showed same result pattern
WM x FLUID INTELLIGENCE
- “working” component of WM predicts fluid intelligence; simple STM doesn’t
- fluid/general intelligence involves “executive attention” component of WM
- memory representations = maintained in highly active state in presence of interference
- representations may reflect action plans/goal states/task-relevant stimuli in environment
WHY IS WM IMPORTANT TO INTELLIGENCE?
DUNCAN ET AL. (2012)
- carried out studies to suggest that it’s the ability to follow complex set of task rules that underlies fluid intelligence
- this ability depends in turn on ability to deconstruct complex task into separately attended elements
- key role for attention
DUNCAN ET AL. (2012): PROCEDURE
- reasoned that there might be more general process involved in WM task kinds that correlate so closely w/intelligence
- in complex WM tasks pps have to remember set of rules for task performance
- reasoned that it may be this remembering process & implementing set of rules that is most closely associated w/intelligence
- gave pps a task involving complex set of rules
- also gave culture fair IQ test similar to Raven’s Matrices
DUNCAN ET AL. (2012): RESULTS
- strongest correlation = between rule WM/intelligence
- other WM types (ie. complex span (digit/spatial/operation)) correlated w/fluid intelligence BUT not as strongly
- it appears that while process of manipulating/processing info in WM might be key component of fluid intelligence, it’s really construction/use of task rule set that underlies individual difs in fluid intelligence
DUNCAN (2017): PROCEDURE
- effecting fluid intelligence involves construction of “mental program” for task performance aka. subdivide goals to sub-goals to break down complex problems into manageable chunks
- “critical function in fluid intelligence = splitting complex whole into simple separately attended parts”
DUNACN (2017): METHODOLOGY
SEPARATED CONDITION
- all pps perform well on task (even w/low IQ)
COMBINED CONDITION
- correlation between fluid intelligence & performance on task
- low IQ pps perform worse
SUMMARY
- WM underlies fluid intelligence
- WM = NOT simply storage
- it’s also ability to store/use task rules to mentally manipulate info held in memory
- in turn this depends on attention aka. ability to split complex task into simple separately attended parts
