Working memory (WM) has been associated with the acquisition of arithmetic skills, however, the components of WM that underlie this acquisition have not been explored. This study explored the contribution of two WM systems (the phonological loop and the central executive) to mathematical performance in young children. The results showed that a…

To study age-related improvements in information processing, a release from proactive interference (PI) procedure was used with 144 children in conjunction with a running memory task. For class of item and acoustic similarity, evidence was found for PI release with age, but there was no evidence of a relationship between short-term memory (STM)…

A three-stage model for the evolution of theories of intelligence is proposed and applied to understanding the evolution of correlationally based and experimentally based theories of intelligence. In stage one, alternative conceptions compete. In subsequent stages, alternative conceptions, which combine elements of prior approaches, emerge and…

In three experiments, differences in EEG alpha activity between 30 gifted and 30 average individuals were studied. Results support the hypothesis that higher alpha power during information processing displayed by gifted individuals may derive from the nonuse of many brain areas not required for the problem at hand. (SLD)

Data on specific cognitive abilities for 86 children ages 6 to 12 from an allelic association study found three DNA markers significantly associated with specific cognitive ability scales after the effects of general intelligence were removed. These preliminary results support the hierarchical model predicted by genetic research. (SLD)

Examined the assumption that Spearman's law acts unsystematically and approximately uniformly for various subtests of cognitive ability in an IQ test battery when high- and low-ability IQ groups are selected. Data from national standardization samples for Wechsler adult and child IQ tests affirm regularities in Spearman's "Law of Diminishing…

Studied the influence of task content and sex on the relationship between intelligence and cortical activation in 26 males and 25 females administered verbal, numerical, and figural versions of an elementary cognitive task. Results suggest comparatively lower cortical activation in more intelligent individuals, but the pattern interacted with sex…

Studied whether genetic variability explained some of the variance in coincidence timing and whether common genetic factors accounted for the association with intellectual functioning using 55 pairs of 16-year-old twins. Results suggest that the genetic influence operating on coincidence timing skills was of similar magnitude to that of response…

College undergraduates learned word lists involving three-term contingencies (stimulus-response-outcome). Learning rate was correlated approximately 0.5 with scores on Raven's Advanced Progressive Matrices (Raven) but did not correlate significantly with several tasks (inspection time, card-sorting, trail-making, PASAT) shown to be associated with…

Jensen has reported reaction-time (RT) studies indicating that various parameters correlate significantly with IQ. Two parameters of interest are slope of RT across set size and increasing correlations of RT with IQ as set size increases. After reviewing these studies, the author concludes that Jensen's claims are unwarranted. (Author/BW)

Tested 133 college students in Germany with new tasks and 6 working memory marker tasks. Results reveal three working memory functions: simultaneous storage and processing; supervision; and coordination of elements into structures. Each function could be subdivided into distinct components of variance. (SLD)

Whether IQ level exerts a differential effect on the impairment of cognitive performance induced during acute hypoglycemia was studied for 24 nondiabetic adults. At various levels of hypoglycemia, no overall effect of IQ on deterioration was noted. Higher IQ did not apparently protect against adverse effects. (SLD)

The dendritic structure of layer II-III pyramidal neurons of the parietal cortex in 41 Long-Evans rats was compared to behavioral assessments of attention to novelty, response flexibility, and reasoning. A significant correlation between dendritic arborization and behavioral performance was not demonstrated. (SLD)

Used the classical twin design with 390 pairs of twins to study the influence of genetic factors on the large phenotypic variation in inspection time (IT) and whether the well-established IT-IQ association could be explained by a common genetic factor. Findings provide potentially important information for the biological bases of the…

Two experiments involving 45 and 48 undergraduate students, one introducing a same-different letter discrimination tasks and the other exploring the effects of practice on inspection time (IT), suggest that at least one component of mental speed that is sensitive to practice may be an important factor underlying the correlation between IT and IQ.…