Anticipatory control of postural and task muscles during rapid arm flexion

A multicomponent pattern of premovement (anticipatory) activity in both task and postural muscles was examined for a unilateral rapid arm flexion movement (Belen'kii, Gurflnkel, & Pal'tsev, 1967) performed under simple visual reaction-time conditions. Subjects performed 30 right- and 30 left-side responses on each of four consecutive days. The anticipatory postural muscle activity may be considered a valid component of voluntary unilateral arm flexion. Invariances and variability in the spatial and temporal characteristics of the neuromuscular pattern are described in relationship to behavioral and motor control models of response organization. It is suggested that some temporal patterning among response components may not be preprogrammed centrally.     

A bayesian approach to confirmatory factor analysis

Confirmatory factor analysis is considered from a Bayesian viewpoint, in which prior information on parameter is incorporated in the analysis. An iterative algorithm is developed to obtain the Bayes estimates. A numerical example based on longitudinal data is presented. A simulation study is designed to compare the Bayesian approach with the maximum likelihood method.Computer facilities were provided by the Computer Services Center, The Chinese University of Hong Kong.     

Two logit models for external analysis of preferences

A logit vector model and a logit ideal point model are presented for external analysis of paired comparison preference judgments aggregated over a homogeneous group. The logit vector model is hierarchically nested within the logit ideal point model so that statistical tests are available to distinguish between these two models. Generalized least squares estimation procedures are developed to account for heteroscedastic sampling error variances and specification error variances. Two numerical illustrations deal with judgments concerning employee compensation plans and preferences for salt and sugar in the brine of canned green beans.     

FUNCTIONAL ASSESSMENT,CURRICULAR REVISION,AND SEVERE BEHAVIOR PROBLEMS

An adolescent female with multiple handicaps and a long history of severely disruptive behavior participated in a functional assessment linked directly to specific revisions in her school curriculum. During Phase 1, reversal designs were used to test hypotheses pertaining to antecedent and auricular influences on problem behavior. During Phase 2, a multiple baseline across afternoon and morning time periods demonstrated that the auricular revisions were effective in eliminating severely disruptive behavior and increasing on-task responding. Data also showed that inappropriate “psychotic” speech was reduced and appropriate social interactions were increased. Follow-up results showed that the changes were maintained throughout the school year. Questionnaire data provided social validation of the procedures and outcomes. The findings are discussed in relation to their implications for functional assessment, individualized curricula, and positive programming for students with disabilities and serious behavior problems.     

Black Students' Reactions to Feedback Conveyed by White and Black Teachers1

The present investigation examined some processes mediating self-fulfilling prophecies among black students. Specifically, we hypothesized that feedback conveyed by black and white teachers would differentially influence black students' perceptions of how the teacher viewed their success/failure, effort, ability, luck and task difficulty. In addition, we hypothesized that negative feedback would affect perceptions of evaluations differently than positive feedback. Ninety black undergraduates participated in an experiment in which a black or white teacher (confederate) expressed one of five evaluative feedback responses to a student's score on an analogies test. The results provided partial support for the first hypothesis: black female students perceived white teachers as assessing their performance less positively: that is, they perceived them to underestimate their ability and the difficulty of the task. Negative feedback also led students to believe the teacher held an unfavorable but inaccurate impression of their ability and effort, and that the teacher underestimated the difficulty of the task. These findings suggest that black students—black females in particular—may assume that white teachers hold less favorable assessments of them than black teachers and all students may be sensitive to negative evaluations.     

Psychometric properties of attitudinal measures of behavioral treatment in geriatric settings

Internal consistency of two forms of the Geriatric Treatment Acceptability Survey (GTAS) and the Attitudes toward Behavior Analysis Scale (ABAS), a global measure of attitudes toward behavior modification, was evaluated. Alpha coefficients regarding treatment acceptability ratings for GTAS Form H were: (a) wandering 0.94; (b) hoarding 0.96; (c) disruptive behavior 0.92; (d) property destruction 0.95; and (e) aggression 0.94. Internal consistency for Form NH was: (a) wandering 0.96; (b) hoarding 0.97; (c) disruptive behavior 0.96; (d) property destruction 0.97; and (e) aggression 0.76. Internal consistency of the ABAS resulted in alpha coefficients of 0.90 (total score); 0.87 (ethics and humaneness); and 0.76 (use). These measures appear useful in assessing older adults, nursing home patients' and geriatric nursing staffs' global and specific attitudes regarding the use of behavioral treatments with older adults. Further research is needed to establish psychometric constructs assessed by the instruments and sensitivity to detecting change in attitudes based on educational or clinical interventions.     

Covariance structure analysis in several populations

This paper is concerned with the study of covariance structural models in several populations. Estimation theory of the parameters that are subject to general functional restraints is developed based on the generalized least squares approach. Asymptotic properties of the constrained estimator are studied; and asymptotic chi-square tests are presented to evaluate appropriate model comparisons. The method of multipliers and the standard reparametrization technique are discussed in obtaining the estimates. The methodology is demonstrated by a set of real data.Computer facilities were provided by the Computer Services Center, The Chinese University of Hong Kong. The authors are indebted to several anonymous reviewers for suggestions for improvement of this paper.