Inhibition in ADHD,aggressive, and anxious children: A biologically based model of child psychopathology

In this study the stop signal task was employed to investigate inhibitory control in 15 children with attention deficit hyperactivity disorder (ADHD), 18 aggressive and 20 anxious children, and a group of 17 normal controls. The psychopathological groups were recruited from special educational services. Parent, teacher, and child questionnaires were used to select children with pervasive disorders. Controls attended regular classes and scored low on all questionnaires. Based on Quay's model of child psychopathology (Quay, 1988, 1993), we hypothesized a deficit in inhibitory control in children with externalizing disorders, whereas anxious children were predicted to be overinhibited. The ADHD group and the aggressive group showed poor inhibitory control and a slower inhibitory process. No evidence of overinhibition was found in anxious children.     

A transactional analysis of biobehavioral systems

The system of behavior [B] consists of those transactional interrelationships between organism [O] and environment [E] that govern their commerce. The biological significance of such [O]-[E] interrelationships, their truing through learning, as well as those systems involved in the subordinate and superordinate regulation of behavior, are clear when life, itself, is seen as an emergent property of the [O]-[E] complex. In addition, a systems view of these hierarchically organized complexities suggests that they adaptively self-stabilize and self-organize, over time, as they participate in [L], the organism-environment complex. Such a transactional analysis of biobehavioral systems resonates well with the most basic axioms of Pavlov’s paradigm.     

Fourier analysis of movement patterns in pigeons

Fourier analysis describes the amount of variation in a time series by partitioning it into sinusoids of different amplitudes and wavelengths and quantifying the extent to which these waves are synchronized. The importance of a given wave is represented by its contribution to the explained variance of the time series. To illustrate its potential application to the study of movement, Fourier analysis was used to quantify the movement patterns of 2 pigeons on a variable-interval (VI) and a variable-time (VT) schedule of reinforcement. For comparison, the movements of 2 pigeons that did not receive reinforcement were similarly analyzed. Characteristic frequencies were higher during VI than during VT, and relatively low during nonreinforcement. We concluded that Fourier analysis can be used to represent movement patterns compactly, study their periodicity, stereotypy, and resonance, and assist in computer simulations and models of movement.     

The children of Mexican-American migrant workers: A population at risk?

The present study assessed intellectual, academic, and emotional strengths and weaknesses for a group of Mexican-American children of migrant farm workers. In order to test the vulnerability hypothesis, the test profiles of these children were contrasted with those of two groups of black children with similar demographic makeup. The children of one group (Clinical Black) had been referred previously for a psychological consultation while the children of the other (Nonreferred Black) had not. Across dependent measures, between-groups contrasts tended to describe the scores of the Migrant children as similar to those of the Clinical Black children and significantly below those of the Nonreferred Black children. The findings suggested specific intellectual, academic, and emotional vulnerabilities of the Migrant children and demonstrated the need to develop ameliorative programs for these children.The authors wish to thank the staff of C & Y, University of Virginia Hospital, especially Ms. Deborah Johnson and Ms. Suzanne Canale, whose cooperation and assistance made this project possible.