While
working on part 4 of my series of presentations (which will
be about short term
memory), I found this paper:
Melby – Lervag, M. and Hulme, C. Is working memory training effective? A meta
analytic review. Developmental
Psychology 2013, vol 49 no. 2, 270-291.
This
meta-analysis reviewed several research based
computerized working memory training
methods.
Before
shortly reviewing it, I'll define short term memory, memory span and working
memory within the CHC
framework. These definitions
are from this excellent chapter:
Schneider, W.
J.,& McGrew, K. (2012). The Cattell-
Horn-Carroll model of intelligence.
In, D. Flanagan & P. Harrison (Eds.), Contemporary Intellectual
Assessment: Theories, Tests, and Issues (3rd ed.) (p. 99-144). New York:
Guilford.
Within
CHC framework, short term memory is the ability to encode, maintain and
manipulate information in one's immediate awareness. There are 2 narrow abilities within
short
term memory:
1.
memory span – the ability to encode information, maintain it in immediate
awareness and immediately reproduce it in the sequence in which it was
represented.
2.
working memory capacity: the ability to direct the focus of
attention to perform relatively simple manipulations of information within immediate
awareness while avoiding distracting stimuli and engaging in controlled
searches for information in long term memory.
Back to the Melby – Lervag and
Hulme paper:
A. Interesting facts from this paper:
Working
memory reflects a domain –general cognitive capacity and not modality specific
systems (verbal vs. visual).
Working
memory capacity places a general limitation on attentional capacity. The unique variance measured by working
memory tasks that is not shared with memory span is executive attention. That's why working memory (but not memory
span) correlates very highly with fluid ability and executive attention. Some say that working memory is identical to
fluid ability and executive control. This
leads to the hypothesis that people with high working memory capacity will
perform better on tasks requiring the inhibition of distracting information.
B. Results of the meta - analysis
The
meta – analysis included 23 studies of training methods which had randomized controlled
trials and at least 2 week interventions. Participants were mostly healthy and typically
developing children and adults.
It turned out that the training programs yield
short term improvements
on working memory tasks (tasks
close to those trained). These improvements
are not sustained after 9 months for verbal working memory, and might be
modestly sustained after 5 months for visuospatial working memory.
There was no evidence that working memory training roduces generalized
gains to other skills
like verbal ability, word decoding or arithmetic, even right after training.
To conclude, the findings cast strong doubts on claims
that working
memory training is effective in improving
cognitive ability and scholastic
achievement.