Colom 2010



“Improvement in working memory is not related to increased intelligence scores” (full text) trained 173 students on WM tasks (such as the reading span task) with randomized difficulties, and found no linked IQ improvement; the IQ tests were “the Advanced Progressive Matrices Test (APM) along with the abstract reasoning (DAT-AR), verbal reasoning (DAT-VR), and spatial relations (DAT-SR) subtests from the Differential Aptitude Test Battery”. None were speeded as in Jaeggi 2008. Abstract:



    “The acknowledged high relationship between working memory and intelligence suggests common underlying cognitive mechanisms and, perhaps, shared biological substrates. If this is the case, improvement in working memory by repeated exposure to challenging span tasks might be reflected in increased intelligence scores. Here we report a study in which 288 university undergraduates completed the odd numbered items of four intelligence tests on time 1 and the even numbered items of the same tests one month later (time 2). In between, 173 participants completed three sessions, separated by exactly one week, comprising verbal, numerical, and spatial short-term memory (STM) and working memory (WMC) tasks imposing high processing demands (STM–WMC group). 115 participants also completed three sessions, separated by exactly one week, but comprising verbal, numerical, and spatial simple speed tasks (processing speed, PS, and attention, ATT) with very low processing demands (PS-ATT group). The main finding reveals increased scores from the pre-test to the post-test intelligence session (more than half a standard deviation on average). However, there was no differential improvement on intelligence between the STM-WMC and PS-ATT groups.”