Working memory: Is it the new IQ?

Working memory, our ability to process and remember information, is linked to a range of cognitive activities from reasoning tasks to verbal comprehension. There is also extensive evidence of the relationship between working memory and learning outcomes. However, some researchers suggest that working memory is simply a proxy for IQ and does not make a unique contribution to learning outcomes. Here we show that children's working memory skills at 5 years of age was the best predictor of reading, spelling, and math outcomes six years later. IQ, in contrast, accounted for a smaller portion of unique variance to reading and math skills, and was not a significant predictor of spelling performance. Our results demonstrate that working memory is not a proxy for IQ, but rather represents a dissociable cognitive skill with unique links to learning outcomes. Critically, we find that working memory at the start of formal education is a more powerful predictor of subsequent academic success than IQ. This result has important implications for education, particularly with respect to developing intervention and training. It appears that we should target our efforts in developing working memory skills in order to see gains in learning

Working memory in children with developmental disorders

The aim of the present study was to directly compare working memory skills across students with different developmental disorders to investigate whether the uniqueness of their diagnosis would impact memory skills. The authors report findings confirming differential memory profiles on the basis of the following developmental disorders: Specific Language Impairment, Developmental Coordination Disorder (DCD), Attention-Deficit/Hyperactivity Disorder, and Asperger syndrome(AS). Specifically, language impairments were associated with selective deficits in verbal short-term and working memory, whereas motor impairments (DCD) were associated with selective deficits in visuospatial short-term and working memory. Children with attention problems were impaired in working memory in both verbal and visuospatial domains, whereas the children with AS had deficits in verbal short-term memory but not in any other memory component. The implications of these findings are discussed in light of support for learning

Towards validation of a new computerised test of goal neglect: preliminary evidence from clinical and neuroimaging pilot studies

Objective: Goal neglect is a significant problem following brain injury, and is a target for rehabilitation. It is not yet known how neural activation might change to reflect rehabilitation gains. We developed a computerised multiple elements test (CMET), suitable for use in neuroimaging paradigms. Design: Pilot correlational study and event-related fMRI study. Methods: In Study 1, 18 adults with acquired brain injury were assessed using the CMET, other tests of goal neglect (Hotel Test; Modified Six Elements Test) and tests of reasoning. In Study 2, 12 healthy adults underwent fMRI, during which the CMET was administered under two conditions: self-generated switching and experimenter-prompted switching. Results: Among the clinical sample, CMET performance was positively correlated with both the Hotel Test (r = 0.675, p = 0.003) and the Modified Six Elements Test (r = 0.568, p = 0.014), but not with other clinical or demographic measures. In the healthy sample, fMRI demonstrated significant activation in rostro-lateral prefrontal cortex in the self-generated condition compared with the prompted condition (peak 40, 44, 4; ZE = 4.25, p(FWEcorr) = 0.026). Conclusions: These pilot studies provide preliminary evidence towards the validation of the CMET as a measure of goal neglect. Future studies will aim to further establish its psychometric properties, and determine optimum pre- and post-rehabilitation fMRI paradigms

Measurement invariance in the assessment of people with an intellectual disability

Intellectual assessment is central to the process of diagnosing an intellectual disability and the assessment process needs to be valid and reliable. One fundamental aspect of validity is that of measurement invariance, i.e. that the assessment measures the same thing in different populations. There are reasons to believe that measurement invariance of the Wechsler scales may not hold for people with an intellectual disability. Many of the issues which may influence factorial invariance are common to all versions of the scales. The present study, therefore, explored the factorial validity of the WAIS-III as used with people with an intellectual disability. Confirmatory factor analysis was used to assess goodness of fit of the proposed four factor model using 13 and 11 subtests. None of the indices used suggested a good fit for the model, indicating a lack of factorial validity and suggesting a lack of measurement invariance of the assessment with people with an intellectual disability. Several explanations for this and implications for other intellectual assessments were discussed

Resting state connectivity and cognitive performance in adults with cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy

Cognitive impairment is an inevitable feature of cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), affecting executive function, attention and processing speed from an early stage. Impairment is associated with structural markers such as lacunes, but associations with functional connectivity have not yet been reported. Twenty-two adults with genetically-confirmed CADASIL (11 male; aged 49.8 ± 11.2 years) underwent functional magnetic resonance imaging at rest. Intrinsic attentional/executive networks were identified using group independent components analysis. A linear regression model tested voxel-wise associations between cognitive measures and component spatial maps, and Pearson correlations were performed with mean intra-component connectivity z-scores. Two frontoparietal components were associated with cognitive performance. Voxel-wise analyses showed an association between one component cluster and processing speed (left middle temporal gyrus; peak −48, −18, −14; ZE = 5.65, pFWEcorr = 0.001). Mean connectivity in both components correlated with processing speed (r = 0.45, p = 0.043; r = 0.56, p = 0.008). Mean connectivity in one component correlated with faster Trailmaking B minus A time (r = −0.77, p < 0.001) and better executive performance (r = 0.56, p = 0.011). This preliminary study provides evidence for associations between cognitive performance and attentional network connectivity in CADASIL. Functional connectivity may be a useful biomarker of cognitive performance in this population

It is better than you think: fluid intelligence across the lifespan

The growth and decline of fluid intelligence is associated with brain structural changes. For example, development of fluid IQ is associated with cortex thickness during the critical period between 6 to 12 years old. On the other end of the lifespan, poor performance in cognitive functioning is attributed to a decrease of frontal gray matter density in elderly populations. In particular, there is a sharp decline in fluid IQ scores after 65 years of age. There is substantial evidence that working memory and fluid intelligence (Gf) share neural substrates, such as the prefrontal and parietal cortices. However, very little research has examined whether the pattern of growth and decline in working memory mirrors that of fluid intelligence. For example, does the decline of working memory skills in elderly populations mirror fluid intelligence? Is the rate of working memory decline similar to the rate of growth