Evaluating the decay gradient for collinearity bias with lateral displacement from the axis of induction

The misperception of alignment which is found in many geometric illusions can be quantified using relatively simple stimulus configurations. Perceived collinearity of one segment (designated as the test segment) is biased by a second segment (designated as the induction segment), with the size of effect being a function of the relative angle between the two segments. The process can be described as angular induction. The strength of bias is greatest when the induction segment is centered at the tip of the test segment. Tong and Weintraub have reported that lateral displacement from the tip, i.e., at right angles to the axis of the induction segment, produces a sharp drop in the strength of effect. This decline is described as a decay gradient for the angular induction. One experiment replicates and provides better quantification of this decay gradient. Two other experiments examine the decay gradient using a pair of induction segments, one on each side of the tip of the test segment. Displacement of the segments (either in the same direction or in opposite directions) produces substantially the same gradient of effect. Therefore, previous evidence of tandem boosting of effect for segment pairs does not depend on collinearity among the stimulus components. Finally, a fourth experiment finds that an induction segment which is at a fixed position and orientation differentially affects the influence of a variable induction segment. At some angles the influence of the variable segment is augmented, and at others it is suppressed. These findings are discussed in a neuroreductionist context, and a simple model for angular induction is presented.     

EFFECTS OF REINFORCEMENT HISTORY AND INSTRUCTIONS ON THE PERSISTENCE OF STUDENT ENGAGEMENT

We examined the effects of three reinforcement histories on the persistence of task engagement by 2 fourth-grade students using a partially counterbalanced ABCDBCD design. In each condition, an experimenter made four student contacts during the first 2 min of each session (reinforcement baseline), followed by an 8-min extinction period. The reinforcement history that contained an instructional control component produced the greatest persistence in student engagement. The applied relevance of instructional control is discussed.     

EMERGENCE OF REINFORCER PREFERENCE AS A FUNCTION OF SCHEDULE REQUIREMENTS AND STIMULUS SIMILARITY

Tustin (1994) recently observed that an individual's preference for one of two concurrently available reinforcers under low schedule requirements (concurrent fixed-ratio [FR] 1) switched to the other reinforcer when the schedule requirements were high (concurrent FR 10). We extended this line of research by examining preference for similar and dissimilar reinforcers (i.e., those affecting the same sensory modality and those affecting different sensory modalities). Two individuals with developmental disabilities were exposed to an arrangement in which pressing two different panels produced two different reinforcers according to progressively increasing, concurrent-ratio schedules. When two dissimilar stimuli were concurrently available (food and a leisure item), no clear preference for one item over the other was observed, regardless of the FR schedules in effect (FR 1, 2, 5, 10, and 20). By contrast, when two similar stimuli were concurrently available (two food items), a clear preference for one item emerged as the schedule requirements were increased from FR 1 to FR 5 or FR 10. These results are discussed in terms of implications for conducting preference assessments and for selecting reinforcers to be used under training conditions in which response requirements are relatively high or effortful.     

BEHAVIORAL PERSISTENCE AND VARIABILITY DURING EXTINCTION OF SELF-INJURY MAINTAINED BY ESCAPE

The self-injurious escape behavior of a developmentally disabled adult was treated with extinction. Results of a reversal design showed substantial bursts of responding when extinction was introduced and reintroduced: self-injury remained at a variable and elevated rate for some time before stable, low rates were observed. Data on aggression, a nontarget behavior during both baseline and treatment, showed a pattern similar to that seen for self-injury during the extinction conditions.     

A preventive,psychoeducational approach to increase perceived social support

Investigated the effects of a 13-week preventive, psychoeducational intervention program to improve perceived social support. Fifty-one, low-perceived support, community residents were randomly assigned to an intervention or wait-list control condition. Intervention subjects received training in social skills and cognitive reframing regarding the self and social relations. The intervention led to increased perceived social support from family, but not from friends. As hypothesized by social cognition models, increases in perceived support appeared to be mediated by changes in self-esteem and frequency of self-reinforcement. Further, such changes in cognition about the self were larger than the changes observed for perceived support, suggesting that it may be easier to change cognition about the self than perceptions of support.     

Assessing Multicultural Counseling Competence: A Review of Instrumentation

The authors review four new instruments designed to assess multicultural counseling competence in trainees and practicing professionals. The Cross-Cultural Counseling Inventory—Revised (CCCI-R), the Multicultural Counseling Awareness Scale—Form B (MCAS:B), the Multicultural Counseling Inventory (MCI), and the Multicultural Awareness-Knowledge-and Skills Survey (MAKSS) were each critically reviewed in terms of item development, psychometric properties, and pragmatic utility. Specific research suggestions for continued empirical validation on the instruments are posited, and strong cautions regarding their current use in training are leveled.     

Extra-legal factors and product liability: The influence of mock jurors' demographic characteristics and intuitions about the cause of an injury

Two experiments were performed to investigate the role of extra-legal factors in a simulated product liability trial. In cases where the factual evidence was identical, subjects' liability judgments varied as a function of the case-specific factor of the alleged source of the plaintiffs injury. In deciding cases differently depending on the alleged cause, subjects relied on intuitions about what injury sources are more or less likely to cause a certain kind of injury. Juror-specific factors also influenced subjects' verdicts. There was no difference between students and non-students, but race and SEC—factors that are often correlated with student status—did affect subjects' verdicts. Low-SES and minority subjects were more likely to find the defendant liable than high-SES and white subjects. The results are considered in terms of general decision-making processes, and the implications for jury selection and mock jury research are discussed.     

Potentiating group psychotherapy for bulimia with ancillary rational-emotive-hypnotherapy

A rational-emotive-hypnotherapy (REH) treatment was administered to five bulimic females who were concurrently participating in electic group psychotherapy. A within-group time series analysis design was employed to examine subjects' binge and purge symptoms. The combined treatments produced a declining frequency in symptoms for four subjects across three phases of the study. REH was responsible for 4 out of 8 possible treatment effects and appeared to potentiate the group psychotherapy. A theoretical explanation is offered for the REH effects along with recommendations for future REH with bulimics. This study was presented as a paper to the annual meeting of the American Psychological Association, 1982, Washington, DC. Appreciation is extended to Don W. Ball, Ph.D. for editorial and technical assistance in the preparation of this article.     

Carnapian inductive logic for Markov chains

Carnap's Inductive Logic, like most philosophical discussions of induction, is designed for the case of independent trials. To take account of periodicities, and more generally of order, the account must be extended. From both a physical and a probabilistic point of view, the first and fundamental step is to extend Carnap's inductive logic to the case of finite Markov chains. Kuipers (1988) and Martin (1967) suggest a natural way in which this can be done. The probabilistic character of Carnapian inductive logic(s) for Markov chains and their relationship to Carnap's inductive logic(s) is discussed at various levels of Bayesian analysis.