Foraging for brain stimulation: toward a neurobiology of computation

The self-stimulating rat performs foraging tasks mediated by simple computations that use interreward intervals and subjective reward magnitudes to determine stay durations. This is a simplified preparation in which to study the neurobiology of the elementary computational operations that make cognition possible, because the neural signal specifying the value of a computationally relevant variable is produced by direct electrical stimulation of a neural pathway. Newly developed measurement methods yield functions relating the subjective reward magnitude to the parameters of the neural signal. These measurements also show that the decision process that governs foraging behavior divides the subjective reward magnitude by the most recent interreward interval to determine the preferability of an option (a foraging patch). The decision process sets the parameters that determine stay durations (durations of visits to foraging patches) so that the ratios of the stay durations match the ratios of the preferabilities.     

Using a Narrative Metaphor: Implications for Theory and Clinical Practice

The evolution of family therapy from a cybernetic metaphor to a narrative metaphor has led us to think differently about therapy, about clients, and about ourselves as therapists. In this article we pursue how this different way of thinking has informed a theoretical understanding of a narrative therapy approach and consequently has opened space for different ways of working clinically. We begin by tracing the evolution to narrative; we consider the implications of social constructionism and its political effects; and we complete the discussion by focusing on narrative theory. We then show how the clinical work follows logically and is coherent with the theoretical considerations. We describe, and illustrate with clinical examples, an innovative approach to working with couples and families with adolescents. In this work we pay attention to the larger cultural stories, including gender constructions, and to personal stories that persons have created to make meaning out of their experience as they interact with one another in a reciprocal meaning-making process. Interventions focus on externalizing the problem narrative that is influencing the client(s), mapping the effects of the problem pattern and/or the totalizing view persons might have of others, and creating space for client(s) to notice preferred actions and intentions. Finally, we close the loop by asking questions of ourselves and others about the effects of working from a narrative metaphor.     

Nodality effects during equivalence class formation: An extension to sight-word reading and concept development

Three students with moderate disabilities were taught to read and match-to-sample sight words comprising stimulus sets based upon the four food groups. We taught students conditional discriminations within four four-member sets using a single-sample/four-comparison procedure. Students were taught A-B, B-C, and C-D conditional discriminations for each of the four potential stimulus classes. Subsequent probes tested for relations based upon symmetry and one-node and two-node transitivity. The performances for all students indicated that symmetric relations emerged before one-node transitive relations, and that one-node transitive relations emerged before two-node transitive relations. These results are consistent with a pattern of responding, referred to as a "nodality effect," in which relations with fewer nodes are demonstrated prior to the demonstration of relations with a greater number of nodes. These results extend this area of research to sight-word reading for students with moderate disabilities.     

BALANCING SOCIAL ACCEPTABILITY WITH TREATMENT EFFECTIVENESS OF AN INTRUSIVE PROCEDURE: A CASE REPORT

The debate over social acceptability of intrusive procedures has led some school districts to adopt policies allowing punishment for only the most extreme forms of destructive behavior. We investigated the effectiveness of selectively implementing punishment for only the most severe topographies of aggression and property destruction, while less extreme behaviors were ignored. Results indicated that severe behaviors were reduced to near-zero levels only when both severe and less severe behaviors were similarly punished.     

HYPOTHESIS-BASED INTERVENTIONS FOR TANTRUM BEHAVIORS OF PERSONS WITH DEVELOPMENTAL DISABILITIES IN SCHOOL SETTINGS

We conducted a functional assessment of problem behaviors of 2 students with developmental disabilities in their classroom environments. Results of the assessments showed that although there were more tantrums in demand than in no-demand conditions, the function of the behavior was to gain attention (positive reinforcement) rather than to avoid or escape demands (negative reinforcement); demand conditions apparently served a discriminative function for the availability of attention. Therefore, intervention was based on the positive reinforcement hypothesis, resulting in a substantial reduction of tantrums for both subjects.     

Deterrence, Opportunity, and Choice

Traditional studies of deterrence have focused on punishment with less regard for the rewards of both crime and noncrime. Influenced by work in economics and behavioral psychology, more recent studies have departed from tradition by incorporating rewards for crime. To this extent, they should be regarded as advances over the more traditional approaches. Notwithstanding these advances, variations in both the probability and magnitude of reward for noncrime have not been systematically included in these more recent theories of choice. In an attempt to determine whether opportunities for noncrime are either central or trivial to the criminal decision-making process, the present study fitted two alternative models to experimental data involving risk-taking: (a) the economic utility model employed by Piliavin, Gartner, Thornton, and Matsueda (1986) in their study of criminal choice; and (b) the satisfaction balance model developed by Gray and Tallman (1984). Results showed that while both models explained significant amounts of variation in the dependent variable, the Gray-Tallman model provided a substantially better fit of the data. Despite limitations inherent in experimental studies as, for example, limitations surrounding the issue of external validity, the findings strongly suggest that opportunities for noncrime are as important as rewards and costs for crime in the process by which criminal decisions are made.     

Responsibility Attributions for Drunken Behavior: The Role of Expectancy Violation1

Research on attributions about drunken aggression has suggested that intoxication serves to excuse the aggressor while increasing blame to the victim. In this study, we examined subjects' responses to a scenario depicting a violent interaction in which intoxication of aggressor and victim, victim's behavior, and aggressor's previous violent background were varied. We predicted that to the extent that the violent act violated the expectations of the observer, alcohol intoxication would serve to decrease dispositional and responsibility attributions to the aggressor. Instead, the findings showed that alcohol use led to increased attributions of causality, blame, and responsibility for both aggressor and victim. The results are discussed in terms of both attribution theory and societal factors influencing the acceptability of excuses involving alcohol.     

Effect of Persuasive Appeals in AIDS PSAs and Condom Commercials on Intentions to Use Condoms1

The study compared the effect of five persuasive appeals used in AIDS PSAs and condom commercials (fear arousal-no sex/condom theme; fear arousal-sex/condom theme; erotic; humorous; factual) on 122 male and 114 female college students' i]ntentions to use and taking of condoms. Results showed that the two fear appeals were more effective than other appeals in increasing intentions to use condoms with a new partner. The fear appeal–no sex/condom theme was more effective than other appeals for increasing intentions to use condoms with a steady partner. Compared to men, women rated commercials as more effective for increasing intentions to use condoms with a new partner. Persuasive appeals had no effect on the taking of free condoms. The best predictor of commercial effectiveness was the degree to which a commercial evoked a high fear of AIDS. Other significant predictors were subjects' a]ttitude toward condom use and commercial qualities of being humorous, romantic, credible, and factual. Implications are that all five types of appeals are potentially effective for use in AIDS PSAs. Recommendations include combining appeals (e.g. fear with erotic) and emphasizing the positive features of condom use.