Tests for stability in linear structural equation systems

Interpretations regarding the effects of exogenous and endogenous variables on endogenous variables in linear structural equation systems depend upon the convergence of a matrix power series. Convergence depends upon the eigenvalues of the structural coefficient matrix. The test for convergence developed by Jöreskog and Sörbom is shown to be only sufficient, not necessary and sufficient.     

Task-specific strategies of mental “rotation” of facial representations

The effects of task demands on the visual comparison of facial patterns and of comparable nonfacial patterns were explored in two studies. The studies yielded two primary findings. First, faces, despite their holistic properties, are not rotated faster than comparable non-face-like patterns, although subjects’ judgments of them were uniformly more rapid than judgments for nonfaces. Second, the nature of the same-different judgment task required of subjects had a large effect on the pattern of results obtained: When stimuli were compared to their mirror images, results indicative of mental “rotation” were obtained. When stimuli were compared on the basis of similarity of individual features, the pattern of results was very different. This one manipulation produced effects that exceeded those of all of the other manipulations, including that of rotation.     

Inhibitory avoidance deficit following short-term adrenalectomy in the rat: the role of adrenal catecholamines

Impaired retention of an inhibitory avoidance response was observed in rats subjected to adrenalectomy (ADX) up to 120 hr before the single learning trial. Corticosterone substitution failed to normalize this behavioral deficit. Rats ADX 240 hr prior to the learning trial showed a normalized behavior. Adrenomedullectomy (ADXM) 48 or 240 hr before learning caused a similar impairment as in short-term ADX rats. The 240-hr ADX rats subjected to corticosterone substitution showed the same behavioral deficit as short-term ADX rats or ADXM ones. Immediate postlearning subcutaneous injection of adrenaline in a dose range of 0.005-5.0 micrograms/kg or of noradrenaline (0.005-0.5 microgram/kg) to 48-hr ADX rats resulted in a dose-related improvement of later retention behavior. Higher doses of catecholamines were less or ineffective. Postlearning treatment of 48-hr ADXM rats with adrenaline (0.5-500 micrograms/kg) caused a similar pattern of behavioral changes. It is concluded that adrenal catecholamines play an important role in the modulation of consolidation of memory. In addition, the high circulating ACTH levels that follow long-term ADX may correct for the behaviorial deficit induced by the absence of adrenomedullary catecholamines.     

A Social Learning Approach to Increasing Blood Donations1

A field experiment conducted in high schools throughout the country was aimed at increasing the number of high school students who donate blood. Special interventions that emphasized psychological or educational approaches to heightening motivation to donate, as well as a combined intervention, were compared with the usual approach taken at blood drives. Psychological interventions in which social learning principles (modeling, perceptions of social norms) played important roles either alone or in combination with an educational (informational) approach were more successful in stimulating blood donations than either an educational approach alone or the approaches traditionally followed by the participating local blood centers. The results demonstrated that use of social learning principles in designing interventions to strengthen socially relevant altruistic behavior could be valuable both practically and theoretically.     

Self-Efficacy,Perceptions of Success,and Intrinsic Motivation for Exercise1

A number of investigators have attempted to identify the determinants of continued participation in exercise regimens. Within a social cognitive framework, the present study examined the relationships among self-efficacy cognitions, perceptions of success, and multidimensional intrinsic motivation in the exercise domain. Multivariate analyses of variance indicated that highly efficacious individuals were more intrinsically motivated toward aerobic dance than were their less efficacious counterparts. However, multiple regression analyses revealed both perceptions of success and self-efficacy to account for significant variance in intrinsic motivation at both the composite and dimensional levels. Moreover, perceptions of success were considerably stronger predictors than were efficacy cognitions. The results are discussed in terms of the need for multiple measures of perceived success, the employment of longitudinal designs to determine the direction of causality among these variables, and possible implications for adherence issues.     

FUNCTIONAL COMMUNICATION TRAINING TO REDUCE CHALLENGING BEHAVIOR: MAINTENANCE AND APPLICATION IN NEW SETTINGS

We evaluated the initial effectiveness, maintenance, and transferability of the results of functional communication training as an intervention for the challenging behaviors exhibited by 3 students. Assessment indicated that escape from academic demands was involved in the maintenance of the challenging behaviors. Social attention was also implicated as controlling the behavior of 1 student. The intervention involved teaching alternative assistance-seeking and attention-getting phrases to the students in an effort to replace challenging behavior with these verbal equivalents. Multiple baseline data collected across the 3 students indicated that not only did the intervention substantially reduce challenging behavior but also that these results transferred across new tasks, environments, and teachers, and were generally maintained from 18 to 24 months following the introduction of functional communication training. These results are discussed in light of recent efforts to develop effective interventions for severe challenging behavior and to understand the processes underlying transfer and maintenance of intervention effects.     

Father-child relationships from the preschool years through mid-adolescence

In this study, we examined variations in fathering and father-child relationships from the children's preschool years through mid-adolescence. One hundred seventy-seven fathers with first-born children ages 4, 8, 12, and 16 years responded to five sets of questionnaires tapping four domains of childrearing: practices, attitudes, parental role involvement, and role satisfaction. A multivariate analysis of variance identified significant variability among the four age groups in fathers' use of acceptance in childrearing practices, role involvement (frequency and task sharing), satisfaction with paternal role performance, and attitudes about the modifiability of child behavior. The results contribute new information about the nature of fathering throughout the childhood years and adolescence and provide additional support for the view of parenting as dynamic and responsive to the developmental level and gender-related characteristics of the child.     

Dilthey''s narrative model of human development: Necessary reconsiderations after the philosophical hermeneutics of Heidegger and Gadamer

Paper delivered at theEighth International Human Science Research Conference at Aarhus University (Denmark), 18–22 August 1989.     

Fitting longitudinal reduced-rank regression models by alternating least squares

An alternating least squares method for iteratively fitting the longitudinal reduced-rank regression model is proposed. The method uses ordinary least squares and majorization substeps to estimate the unknown parameters in the system and measurement equations of the model. In an example with cross-sectional data, it is shown how the results conform closely to results from eigenanalysis. Optimal scaling of nominal and ordinal variables is added in a third substep, and illustrated with two examples involving cross-sectional and longitudinal data.Financial support by the Institute for Traffic Safety Research (SWOV) in Leidschendam, The Netherlands is gratefully acknowledged.