Working memory - week 7 (Chris) Flashcards
(19 cards)
1954: H.M. – bilateral removal of the temporal lobe
Severe amnesia – inability to form new long-term memories for events and facts
Preserved short term memory
Preserved procedural memory
1969: K.F – lesion to parietal/occipital cortex
Reduced digit span (short term memory - approx 2 items)
Preserved long-term memory
KF and HM
Double Dissociation between long term memory and short term memory
Baddeley and Hitch (1974): Working Memory
Visuo-spatial sketchpad
Central executive
Phonological loop
Articulatory suppression effect
Subvocal rehearsal impairs short-term memory for words but has no effect on performance of a visuospatial task e.g. chess
Behavioural evidence for separable phonological and visuospatial stores (Baddeley & Hitch)
Articulatory suppression effect
In contrast, chess performance is drastically impaired by performance of a concurrent short term visuospatial memory task
Suggests the existence of two separate systems for temporary storage of information, one phonological and one visuospatial
General Intelligence (Spearman’s ‘g’ factor)
In 1904, Spearman published a paper examining correlations in children between different disparate measures - academic ability (ratings from teachers, performance in exams etc.) and sensory discrimination
Found that correlations were all positive
Factor analysis revealed an underlying factor common to performance of many different kinds of tasks (‘g’ factor) – general intelligence
Two underlying factors of Spearman’s ‘g’ factor
Gf - fluid intelligence
Gc - crystallised intelligence
Fluid intelligence
Reasoning
Problem solving
Crystallised intelligence
General knowledge
Raven’s matrices
Test used to assess fluid intelligence.
Which picture finishes the pattern?
Kyllonen & Christal (1990)
Asked the question: “What underlies our ability to perform reasoning tasks of the kind measured by Gf?”
Gave subjects tests of different processes eg. working memory, general knowledge, processing speed
Also gave subjects reasoning tasks (tests of general – fluid – intelligence)
Problem with digit span tests
Problem with these tests is that they do not distinguish between storage (short term memory) and executive processes (working memory)
Performance depends on a combination of these processes
Evidence that the ‘working’ component of WM, and not simply short-term memory, correlates with fluid intelligence
Kane & Engle (2002)
Complex span task: Solve each maths problem and say word aloud – then recall all 3 words at the end
Simple span task: Say each word aloud then recall all three words at the end
Complex span requires retention of information in WM and in addition requires the active processing, manipulation and updating of this information (Working memory)
Simple span only requires retention of information in WM (Short term memory)
Structural Equation Model
The structural equation model identified 3 factors underlying performance of these tasks – essentially 3 independent cognitive processes that are differentially engaged by these tasks- working memory (WM), short term memory (STM) and processing speed.
They then examined the extent to which these factors correlated with their measure of fluid (or general) intelligence (gF). As you can see, the correlation between working memory and gF was almost perfect. But the correlation between STM and gF was negative. And the correlation between speed and gF was low.
Key distinction between working memory and short term memory
‘Working’ component of working memory predicts fluid intelligence
Simple short term memory capacity does not
Fluid, or general, intelligence involves the ‘executive attention’ component of WM
Rule working memory task
Duncan et al. (2012)
John Duncan reasoned that there might be a more general process involved in the kinds of WM tasks that correlate so closely with intelligence.
In the complex WM tasks subjects have to remember a set of rules for task performance. He reasoned that it may be this process of remembering and implementing a set of rules that is most closely associated with intelligence.
He gave subjects a task involving a complex set of rules and also the kinds of complex span tasks we saw in the previous studies.
Also gave subjects a culture fair IQ test which is similar to the Ravens matrices.
Duncan found that the strongest correlation was between rule WM and intelligence. Other types of WM, such as complex span (digit, spatial or operation) correlated with fluid intelligence but not as strongly.
Thus, it appears that whilst the process of manipulating or processing information in WM might be a key component of fluid intelligence, it is really the construction and use of a set of task rules that underlies individual differences in fluid intelligence.
Duncan (2013)
Effective fluid intelligence involves construction of a ‘mental program’ for task performance – subdivide goals into sub-goals to break down complex problems into manageable chunks.
Duncan et al. (2017)
Separated condition – all subjects perform well on the task, even those with lower IQ
Combined condition – correlation between fluid intelligence and performance on task – low IQ subjects perform worse
