Using more complex items than those commonly employed within the information-processing approach, but still easier than those used in intelligence tests, this study analyzed how the association between processing speed and accuracy level changes as the difficulty of the items increases. The study involved measuring cognitive ability using Raven's…

Responses to items from an intelligence test may be fast or slow. The research issue dealt with in this paper is whether the intelligence involved in fast correct responses differs in nature from the intelligence involved in slow correct responses. There are two questions related to this issue: 1. Are the processes involved different? 2. Are the…

The relationships between processing speed, intelligence, and school achievement were analyzed on a sample of 184 Russian 16-year-old students. Two speeded tasks required the discrimination of simple geometrical shapes and the recognition of the presented meaningless figures. Raven's Advanced Progressive Matrices and the verbal subtests of…

Brain shape might influence cognitive performance because of the relationships between functions, spatial organization, and differential volumetric development of cortical areas. Here we analyze the relationships between midsagittal brain shape variation and a set of basic psychological measures. Coordinates in 2D from 102 MRI-scanned young adult…

Mental chronometry (MC) studies cognitive processes measured by time. It provides an absolute, ratio scale. The limitations of instrumentation and statistical analysis caused the early studies in MC to be eclipsed by the "paper-and-pencil" psychometric tests started by Binet. However, they use an age-normed, rather than a ratio scale, which…

In a population-based sample of 112 nine-year old twin pairs, we investigated the association among total brain volume, gray matter and white matter volume, intelligence as assessed by the Raven IQ test, verbal comprehension, perceptual organization and perceptual speed as assessed by the Wechsler Intelligence Scale for Children-III. Phenotypic…

To explore the possible neural foundations of individual differences in intelligence test scores, we examined the associations between Raven's Matrices scores and two tasks that were administered in a functional magnetic resonance imaging (fMRI) setting. The two tasks were an n-back working memory (N = 37) task and inspection time (N = 47). The…

In this study, cross-cultural differences in cognitive test scores are hypothesized to depend on a test's cultural complexity (Cultural Complexity Hypothesis: CCH), here conceptualized as its content familiarity, rather than on its cognitive complexity (Spearman's Hypothesis: SH). The content familiarity of tests assessing short-term memory,…

It has been established that both domain-specific (e.g. spatial) as well as domain-general (general intelligence) factors influence human cognition. However, the separation of these processes has rarely been attempted in studies using laboratory animals. Previously, we have found that the performances of outbred mice across a wide range of…

In our prior study the negative correlation between Topology, a behavioral measure of fluid reasoning, and adult age diminished with the increase in the level of expertise in a cognitively-demanding domain of expertise in the game of GO. The present fMRI study was designed to investigate neural substrates of Topology. The modified topology…

We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

Various taxonomies of Raven's Advanced Progressive Matrices (APM) items have been proposed in the literature to account for performance on the test. In the present article, three such taxonomies based on information processing, namely Carpenter, Just and Shell's [Carpenter, P.A., Just, M.A., & Shell, P., (1990). What one intelligence test…

A critical review of the theoretical basis and empirical results of the frequency accrual speed test (FAST) developed by D. Vickers and others (1993) leads to the conclusion that the FAST is not appropriately described as an alternative to the inspection time (IT) task, and that results from FAST are not generalizable to IT. (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…