Proposes a parallel distributed-processing (PDP) model to account for choice-reaction-time performance in diverse cognitive and perceptual tasks that are interrelated in terms of stimulus-stimulus and stimulus-response overlap. Simulation results support the PDP model. (SLD)

This study investigated the nature of advance preparation for a task switch, testing 2 key assumptions of R. De Jong's (2000) failure-to-engage theory: (a) Task-switch preparation is all-or-none, and (b) preparation failures stem from nonutilization of available control capabilities. In 3 experiments, switch costs varied dramatically across…

The fundamental relations that underlie cognitive comparisons--''same'' and ''different''--can be defined at multiple levels of abstraction, which vary in relational complexity. We compared response times to decide whether or not two sequentially-presented patterns, each composed of two pairs of colored squares, were the same at three levels of…

This study was designed to explore the placebo-controlled effects of risperidone on cognitive-motor processes, dyskinetic movements, and behavior in children receiving maintenance risperidone therapy. Sixteen children aged 4-14 years with disruptive behavior were randomly assigned to drug order in a crossover study of risperidone and placebo for 2…

The aim of this study was to identify promising endophenotypes for intelligence in children and adolescents for future genetic studies in cognitive development. Based on the available set of endophenotypes for intelligence in adults, cognitive tasks were chosen covering the domains of working memory, processing speed, and selective attention. This…

Background: Attention deficit hyperactivity disorder (ADHD) is a prevalent neuropsychiatric disorder in childhood with established problems in cognitive control and associated fronto-striatal circuitry. More recently, fronto-cerebellar circuits have been implicated in this disorder. Both of these circuits are important in predicting the occurrence…

Deficient behavioral inhibition (BI) processes are considered a core feature of attention deficit/hyperactivity disorder (ADHD). This meta-analytic review is the first to examine the potential influence of a wide range of subject and task variable moderator effects on BI processes--assessed by the stop-signal paradigm--in children with ADHD…

Three experiments were carried out to investigate hemispheric asymmetry in color processing among normal participants. In Experiment 1, it was shown that the reaction times (RTs) of the dominant and non-dominant hands assessed using a visual target presented at the central visual field, were not significantly different. In Experiment 2, RTs of…

The relation between general intelligence (psychometric "g") and temporal resolution capacity of the central nervous system was examined by assessing performance on eight different temporal tasks in a sample of 100 participants. Correlational and principal component analyses suggested a unitary timing mechanism, referred to as temporal "g".…

Working memory is an important theoretical construct among children, and measures of its capacity predict a range of cognitive skills and abilities. Data from 9- and 11-year-old children illustrate how a chronometric analysis of recall can complement and elaborate recall accuracy in advancing our understanding of working memory. A reading span…

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)

Nine children with Down's syndrome were compared to two groups of nonretarded children, one similar in CA, the other a chronologically younger group of similar MA. The event-related brain potential and reaction time results indicated that Downs syndrome Ss processed some types of auditory information more slowly than the other groups. (Author/CL)

Secondary task performance was used to evaluate the attentional demands of encoding the first letter in a sequential letter-match task. Unlike earlier studies, comparing secondary task performance between two primary task conditions indicated that letter encoding involves attention. Performance during the intertrial interval varied with subjects'…

Lateralized readiness potentials (LRPs) were used to determine the stage(s) of reaction time (RT) responsible for speed-accuracy trade-offs (SATs). Speeded decisions based on several types of information were examined in 3 experiments, involving, respectively, a line discrimination task, lexical decisions, and an Erikson flanker task. Three levels…