Punished and Nonpunished Responding in A Multiple Schedule in Humans: A Brief Report

Four male subjects responded on a multiple schedule in which responding was maintained by a random interval 20-sec (RI20) schedule of point presentation. Responding was suppressed in alternating components by an added variable ratio 30 (VR30) schedule of point subtractions. Each component was accompanied by distinctive stimulus lights. Subjects were exposed to the multiple schedule from the initial session. Two subjects experienced four 50-min sessions daily (Experiment 1) and the other two subjects participated in one 50-min session daily (Experiment 2). Once responding in the punished components had stabilized, responding in the nonpunished components continued to increase across sessions. Nonpunished responding did not stabilize even after as many as 36 sessions. These results are discussed in the context of previous studies using animals which employed multiple schedules with punished and nonpunished response contingencies.

     

Perceived parental inconsistency as a factor in the emotional development of behaviour-disordered children

55 English-speaking institutionalized adolescents (37 boys and 18 girls between ages of 14 and 19 yr.) were given questionnaires measuring perceived parental inconsistency and different components of emotional development. Canonical correlation analysis indicated that a significant proportion (51%) of the variation in emotional adjustment was accounted for by parental inconsistency. It is suggested that the efficiency of using parents as agents of change for their behaviour-disordered children can be enhanced by including theory on parenteral inconsistency in program content.     

Distorted body image as a risk factor in anorexia nervosa: replication and clarification

This study replicated the results of an earlier one in which college women showing psychological similarities to anorexics indicated an unrealistically larger body-image relative to controls but only if they were relatively thin. This kind of perceptual enhancement was not found when inanimate objects were rated. The proposal that an enhanced body image plays a dynamic role in motivating food restraint (and may increase the risk of becoming anorexic) was supported by an analysis of dieting strategies.     

Structure of learning environment variables under two instructional conditions

The present study investigated the congruence between the factor structures of the learning environment and cognitive variables for mathematics and English courses in Grade 10. Three common factors were obtained in each course. Procedural characteristics and cognitive factors in mathematics were highly similar to the corresponding factors in English. However, the formative characteristics factor identified in mathematics was not congruent to the corresponding factor in English. Learning environment variables produced two factors. These factors resembled the congruent factor properties for the two courses when the learning environment and cognitive variables were factor analyzed together. Implications for learning and instructional research are mentioned.     

Attention and disordered eating behavior: II. Disattention to turbulent inner sensations as a risk factor in the development of anorexia nervosa

The Slade model for development of anorexia nervosa proposes that the female may seek success and control in her life by pursuing a thin body through dieting when faced with serious personal problems. Extending upon this model, the present program of research has sought to identify those characteristics of women generally at-risk for anorexia nervosa that would make dieting behavior especially successful, permitting the progression from food restraint into food aversion. The present studies considered whether heightened and stress-related inner stimulation could interfere with the at-risk woman's sensitivity to hunger sensations, thereby decreasing her motivation to eat. A series of analyses conducted within two studies indicated: (1) a relationship between elevated daily stress, concern over being over-whelmed by inner feelings, and a loss of discrimination regarding sources of inner feelings, (2) a tendency to narrow attentional focus when overloaded with excessive internal stimulation, and (3) diminished sensitivity to hunger sensations for women generally at-risk for anorexia nervosa given a narrowed attentional focus.     

Questions at the general hospital. Ulcerative colitis and Crohn disease in the light of a discussion on the body and soul

The author is an internist in a non-university hospital. He discusses the possibilities and limits of dealing with patients suffering from ulcerative colitis and Crohn's disease. He demonstrates the clinical importance of a psychoanalytic perspective with three case illustrations.     

Modeling item responses when different subjects employ different solution strategies

A model is presented for item responses when different subjects employ different strategies, but only responses, not choice of strategy, can be observed. Using substantive theory to differentiate the likelihoods of response vectors under a fixed set of strategies, we model response probabilities in terms of item parameters for each strategy, proportions of subjects employing each strategy, and distributions of subject proficiency within strategies. The probabilities that an individual subject employed the various strategies can then be obtained, along with a conditional estimate of proficiency under each. A conceptual example discusses response strategies for spatial rotation tasks, and a numerican example resolves a population of subjects into subpopulations of valid responders and random guessers.The first author's work was supported by Contract No. N00014-85-K-0683, project designation NR 150-539, from the Cognitive Science Program, Cognitive and Neural Sciences Division, Office of Naval Research. We are grateful to Murray Aitkin, Isaac Bejar, Neil Dorans, Frederiksen, and Marklyn Wingersky for their comments and suggestions, and to Alison Gooding, Maxine Kingston, Donna Lembeck, Joling Liang, and Kentaro Yamamoto for their assistance with Example 2.     

Falsification and Grünbaum's Duhemian theses

This paper is a detailed critical study of Adolf Grünbaum's work on the Duhemian thesis. I show that (a) Grünbaum's geometrical counterexample to the (D1) subthesis is unsuccessful, even with minimal claims made for what the counterexample is supposed to show, and (b) the (D2) subthesis is not a reasonable one (and cannot correctly be attributed to Duhem). The paper concludes with an argument about the relation between the Duhemian thesis, concerning component hypotheses of a scientific theory, and the view that it is impossible to falsify entire theories conclusively.