Effects of differential reinforcement on the behavior and self-esteem of children with emotional and behavioral disorders

Students in a residential special school for children with emotional and behavioral disorders participated in a study designed to reduce their levels of inappropriate behavior. The residential care staff rated the students' behavioral problems and their class teachers rated their overt self-esteem pre and post intervention. In addition, the students completed self-ratings of their self-esteem. The students were divided into two groups, experimental and control. A multiple baseline across behaviors design was used to assess behavioral changes in the experimental group. Both groups received tangible rewards to the same level but only the experimental group received them contingent upon behaving appropriately. Results showed that the experimental group students made substantial reductions in their levels of inappropriate behavior, which were maintained at a three-month followup. Also, ratings of their behavioral problems by residential child care staff suggested that this improvement in behavior had generalized beyond the classroom to the residential setting. However, no significant differences were found between the pre- and post-intervention ratings of their self-esteem or teacher ratings of their overt self-esteem.     

Social context,student's motivation,and academic achievement: Toward a process model

The purpose of the present research was to propose and test a motivational process model of academic achievement. The model posits that parental, teachers, and school administration support for students' autonomy positively influences students' perceived school competence and autonomy. In turn, perceived school competence and autonomy affect positively self-determined school motivation which in turn influences academic achievement. Two studies using a prospective design tested the adequacy of the model. In Study I, participants were 1,623 ninth-grade students. Results from structural equation modeling supported the motivational model. Participants in Study 2 were 1,098 tenth-grade students. Results from this study corroborated those of Study 1 controlling for students' prior achievement in the ninth grade. The role of self-determinod school motivation in academic achievement is discussed and avenues for future research are considered. This research is part of a larger project that is being funded by grants from the William and Flora Hewlett Foundation; the San Francisco Foundation; the Robert Wood Johnson Foundation; the Danforth Foundation; the Smart Foundations; the Pew Charitable Trusts; the John D. and Catherine T. MacArthur Foundation; the Annenberg Foundation; Spunk Fund, Inc.; the DeWitt Wallace-Reader's Digest Fund, Inc.; Louise and Claude Rosenberg; and the Center for Substance Abuse Prevention, U.S. Department of Health and Human Services. The views expressed in the paper are those of the authors and not necessarily of the funders. We are grateful to the many educators, students, and colleagues who cooperated with us on this project and to several anonymous reviewers who provided helpful suggestions.     

Substance use and violent behavior in adolescence

The relation between substance use and violent behavior in adolescence is reviewed, and each of five competing models of this relation is examined. I begin by presenting background material on adolescent substance use and adolescent violence. I then describe five different models that have been proposed to explain the association between substance use and violent behavior. Next, I review the adolescent literature concerning substance use and violence, noting methodological weaknesses that have plagued this research. I conclude with an evaluation of the five models and suggestions for future research.     

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.     

Signal-processing software for teaching and research in psychoacoustics under UNIX and X-Windows

A package of software is described that generates, analyzes, stores, and displays sampled waveforms. The package is designed for use under UNIX and includes C source code, UNIX manual pages, and tutorial documents. The programs interact via UNIX pipes using an ASCII-text data format, which enables the user to view the data in numerical form as well as through the use of plotting programs. Among many other functions, the programs can do the following: efficiently generate linearphase FIR filters with arbitrary transfer functions; generate impulse responses for rectangular rooms of specified dimensions; convolve waveforms with each other; perform Fourier transformation and inverse Fourier transformation; filter waveforms in the Fourier domain; filter waveforms according to the peripheral frequency selectivity of the human auditory system; cross-correlate waveforms; autocorrelate waveforms; synthesize complex waveforms, including vowel sounds and white noise. The software can read and write a variety of commonly used waveform file formats. The data can be plotted on an X-Window display using thegnuplot software, which has been included in the package. The complete software package is available via anonymous ftp from ftp.ihr.mrc.ac.uk in ~ftp/pub/johncu/wave.tar.Z     

Reduction of the elevator illusion from continued hypergravity exposure and visual error-corrective feedback

Ten subjects served as their own controls in two conditions of continuous, centrifugally produced hypergravity (+2 Gz) and a 1-G control condition. Before and after exposure, open-loop measures were obtained of (1) motor control, (2) visual localization, and (3) hand-eye coordination. During exposure in the visual feedback/hypergravity condition, subjects received terminal visual error-corrective feedback from their target pointing, and in the no-visual feedback/hypergravity condition they pointed open loop. As expected, the motor control measures for both experimental conditions revealed very short lived underreaching (the muscle-loading effect) at the outset of hypergravity and an equally transient negative aftereffect on returning to 1 G. The substantial (approximately 17°) initial elevator illusion experienced in both hypergravity conditions declined over the course of the exposure period, whether or not visual feedback was provided. This effect was tentatively attributed to habituation of the otoliths. Visual feedback produced a smaller additional decrement and a postexposure negative aftereffect, possible evidence for visual recalibration. Surprisingly, the target-pointing error made during hypergravity in the no-visual-feedback condition was substantially less than that predicted by subjects’ elevator illusion. This finding calls into question the neural outflow model as a complete explanation of this illusion.     

Chronic sorrow: A content analysis of parental differences

Sixty-eight mothers and 64 fathers of children with a neural tube defect responded to a questionnaire about chronic sorrow. Mothers reported a mood state change in very intense category from more pessimistic at time of diagnosis to more optimistic at current time. Fathers, although indicating a mood change in the very intense category to more optimistic, also had more pessimistic responses. Parental similarities and differences were also reported in both times and events that triggered the sorrow response. Categories across times and events were primarily related to health care, school/development concerns and social significance. Clinical and research implications of these findings are discussed.