Base-rate effects in category learning: a comparison of parallel network and memory storage-retrieval models

Exemplar-memory and adaptive network models were compared in application to category learning data, with special attention to base rate effects on learning and transfer performance. Subjects classified symptom charts of hypothetical patients into disease categories, with informative feedback on learning trials and with the feedback either given or withheld on test trials that followed each fourth of the learning series. The network model proved notably accurate and uniformly superior to the exemplar model in accounting for the detailed course of learning; both the parallel, interactive aspect of the network model and its particular learning algorithm contribute to this superiority. During learning, subjects' performance reflected both category base rates and feature (symptom) probabilities in a nearly optimal manner, a result predicted by both models, though more accurately by the network model. However, under some test conditions, the data showed substantial base-rate neglect, in agreement with Gluck and Bower (1988b).     

How and when to correct for juror hindsight bias in mental health malpractice litigation: Some preliminary observations

This article examines the hindsight bias in the context of mental health malpractice litigation, analyzes various legal mechanisms for dealing with the bias, and discusses whether the law should strive for debiasing in all mental health malpractice cases.     

Hugs or shrugs: Parental and peer influence on continuity of involvement in sport by female adolescents

The study was designed to examine the influence of significant others (mothers, fathers, and male and female peers) on continuing involvement in sport by adolescent females. Survey data were collected from 376 girls using a forced-choice, self-administered questionnaire. Maintenance of involvement was measured by the proportion of possible years in which the respondents were involved in physical activity within each of three participation contexts (intramural, interschool, and community sport). Several indicators of significant other influence were used. The degree to which involvement in physical activity is maintained is positively related to the source, amount and type of influence received from significant others, and varied by the participation context. Overall, the socializing influence of significant others was able to account for 11% of the variance in intramural activity, 20% of the variance in interschool sport, and 10% of the variance in community-based activity.This study was funded by a grant from Fitness Canada.     

Negativism and countertransference

The purpose of this work is to explore the phenomenon of negativism and the analyst's response to it during the course of analytic work with a patient in whom negativism is a central behavioral pattern. Melville's short story, "Bartleby the Scrivener," describing in telling detail the response of a sympathetic lawyer to profound and pervasive negativism in his legal scribe, is discussed as a literary analogy to the analyst-analysand dyad. Aspects of the concept of negativism within psychoanalysis are discussed. The potential usefulness of understanding certain unexpected countertransference responses to pervasive negativism is explored, as this is a relatively neglected area of psychoanalytic technique. A case is presented describing the analysis of a patient whose character, like Bartleby's, is a mixture of profound negativism along with schizoid, obsessional, and masochistic elements.