Many aspects of cognition decline from middle to late adulthood, but the dimensionality and generality of this decline have rarely been examined. We analyzed 20-year longitudinal data of 6203 middle-aged to very old adults from Greater Manchester and Newcastle-upon-Tyne, UK. Participants were assessed up to eight times on 20 tasks of fluid…

The study investigates the effects of intelligence, perceptual speed and age on intraindividual growth in attentional speed and attentional accuracy over the course of a 6-minute testing session. A sample of 193 subjects completed the Advanced Progressive Matrices and the Vienna Matrices Test representing intelligence, the tests Alertness and…

In a recent paper, Johnson, Bouchard, Krueger, McGue, and Gottesman (2004) addressed a long-standing debate in psychology by demonstrating that the g factors derived from three test batteries administered to a single group of individuals were completely correlated. This finding provided evidence for the existence of a unitary higher-level general…

Individuals scoring high in fluid intelligence tasks generally perform very efficiently in problem solving tasks and analogical reasoning tasks presumably because they are able to select the task-relevant information very quickly and focus on a limited set of task-relevant cognitive operations. Moreover, individuals with high fluid intelligence…

Empirical data suggest that there is at most a very small sex difference in general mental ability, but men clearly perform better on visuospatial tasks while women clearly perform better on tests of verbal usage and perceptual speed. In this study, we integrated these overall findings with predictions based on the Verbal-Perceptual-Rotation (VPR)…

Examined the contribution of perceptual processes to cognitive ability with respect to stimulus complexity, response mode, level of encoding, and attention. Findings for 124 college students show that about 70% of common variance of perceptual processes and cognitive ability was due to attentive processes, with 30% resulting from pre-attentive…

Strategy use, task performance, and perceptions of difficulty were studied for 34 mildly retarded children and 34 who were not retarded. Results showed that retarded children rated tasks more difficult than nonretarded students and responded less well to brief task training. Metacognitive variables predicted recall performance independently of…

Confirmatory factor analysis was used to test models of the relationship between inspection time (IT) and psychometric measures of intelligence in a sample of 134 healthy adults in the United Kingdom. A nested structural equation modeling approach shows that IT is most strongly associated with the Perceptual-Organizational factor of the Wechsler…

Tested 8 individuals with mental retardation or autism and 16 individuals without either condition for their ability to detect a form in a random-dot kinematogram. The presence and generalization of training effects in those who initially did not meet criterion performance suggests that initial failures may be due in part to postperceptual…

Whether cross-sectional rates of decline for brain volume and the Performance Intellectual Quotient of the Wechsler Adult Intelligence Scale-Revised were equivalent over the years 16 to 65 was studied with 196 volunteers. Results indicate remarkably similar rates of decline in perceptual-motor functions and aging brain volume loss. (SLD)

A telephone test battery to assess verbal, spatial, and memory ability and perceptual speed in adolescents was developed. Test materials were mailed to 212 adolescents (members of 54 adoptive and 52 nonadoptive sibling pairs). Results show that telephone testing can be satisfactorily used to assess specific cognitive abilities with less anxiety…

The latency and amplitude of the P300, an event-related potential, during the performance of a memory-scanning task were used as indices of the efficiency of information processing that may mediate individual differences in intelligence. Results with 61 female college students contradict a pure speed of processing explanation of the relationship…

Various experiments demonstrated that the difficulty level of several performance-type intelligence test tasks is determined directly by stimulus and task variables that vary the information to be processed. The implications of these findings for intelligence and the problems of an experimental approach to the measurement of intelligence are…

A large sample of 11-year-olds were observed on a perceptual maze task. Three ability level groups were formed and compared as to overall response paths and specific binary decision configurations. Explanations for observed qualitative differences and discussion of the viability of the experimental approach adopted are presented. (Author/RD)

Demonstrated is a covariance principle that causes the observer to assume that if one aspect of a two-dimensional figure (its perimeter or its area) is conserved, the other aspect must also be conserved (pseudo-conservation). Mentally retarded individuals, assuming no such fixed relationship, correctly judged the changed state of the nonconserved…