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).     

Social anxiety and fear of bodily sensations in panic disorder and agoraphobia: A matched comparison

This study tests the hypothesis that social anxiety and fear of bodily sensations are associated with the development of agoraphobic avoidance behavior in panic disorder patients. Twenty patients with panic disorder were compared to 20 patients with panic disorder with agoraphobia, matched by sex and duration of disorder. The two groups did not differ on measures of fear and frequency of assertive social responses. However, the agoraphobics scored higher on measures of interpersonal sensitivity, depression, feelings of inadequacy, and hostility. They also reported higher fear of bodily sensations. Although definitive conclusions need to be postponed until prospective studies have been conducted, there is evidence suggesting that the development of agoraphobia in panic patients is associated with hypersensitivity to bodily sensations and interpersonal situations.This research was supported by Grant 560-268-009 of the Dutch Organization for Scientific Research.     

Gay Identity Issues Among Black Americans: Racism,Homophobia, and the Need for Validation

There is little available literature on gay and lesbian identity among Black Americans. This exploratory study involved interviewing a total of six Black-American gay men and lesbian women regarding gay identity development issues. Data pertaining to the interviewees' experiences of gay identity development were obtained through a questionnaire of six open-ended questions and an interview with each participant lasting 1 to 2 hours. This article presents some of the significant challenges faced by those who were interviewed regarding their sense of self-acceptance, both as Blacks in the predominantly White gay and lesbian community and as gay men and lesbian women in the predominantly heterosexual Black community. The implications of these issues for future research and counseling intervention are discussed. In this article the term gay identity is generally used in reference to both men and women. When women are being discussed exclusively, however, the term lesbian identity is used.     

Relationship of severity of dementia to caregiving stressors

In studies of individual differences and longitudinal changes in stress and coping among dementia caregivers, assessing severity of patient impairment is critically important. It is proposed that with the progression of dementia, cognitive impairment may steadily increase, but other stressful behavioral symptoms peak at various stages of dementia. Cross-sectional data from 49 caregiving families and longitudinal follow-up data from 48 families suggest that instrumental self-care deficits begin early in dementia, and basic self-care deficits increase with dementia severity, but that many distressing behavioral symptoms decrease in late dementia. Assessments of dementia patient severity should be multidimensional, and increases and decreases in various dementia patient stressors over time should be considered as factors influencing caregiver coping.     

Forecasting the impact of the federal sentencing guidelines

The Sentencing Reform Act of 1984, which created the U.S. Sentencing Commission, required that the commisson consider prison capacity in drafting sentencing guidelines. As part of the commission's efforts to meet this requirement, we developed a computer simulation capable of projecting the impact of the commission's guidelines on future sentences and prison populations. According to our projections, “straight” probation sentences will be reduced significantly under the guidelines. However, reducing the use of probation will generate only modest demands on the prisons, and then mostly for community corrections phased in over the course of 5 years. We also project that, while average time served for violent offenses will increase substantially, average time served for most property crimes will remain largely the same. Finally, while we forecast that federal prison populations will grow markedly by the end of this century, this is more a result of the Anti-Drug Abuse Act of 1986 and the career offender provision of the Comprehensive Crime Control Act of 1984 than a result of the guidelines.     

Mental health expert witnesses: Of science and crystal balls

This article reviews the history of and basis for mental health testimony. It surveys the roles of such experts in the legal system and the concomitant problems with current approaches. Finally, it suggests specific reforms that may improve the use of mental health experts in legal proceedings.     

Perioral somatosensory determinants of nursing behavior in Norway rats (Rattus norvegicus)

Prior to assuming the upright crouching posture over their pups during nursing bouts, lactating rats typically engage in several oral behaviors, including nuzzling, licking and rearranging pups. By acutely depriving dams of various aspects of perioral stimulation from pups (with anesthesia of the mystacial pads or of the tongue, with mouth suturing, or with muzzling), we found the following: (1) Distal stimulation from pups maintains proximity-seeking behavior, but is insufficient to stimulate nursing behavior. (2) Lack of tongue feedback decreases pup licking and hastens the onset of crouching. (3) Snout, but not tongue, contact with pups is required for hovering over them. (4) The position of the dam while hovering over her litter enables the pups to gain access to her ventrum, thereby provoking her upright, crouching posture. (5) Older pups are capable of bypassing the dam's perioral attentions and stimulating crouching directly by burrowing under the dam's ventrum.