Effects of delayed conditioned reinforcement in chain schedules.

The contingency between responding and stimulus change on a chain variable-interval 33-s, variable-interval 33-s, variable-interval 33-s schedule was weakened by interposing 3-s delays between either the first and second or the second and third links. No stimulus change signaled the delay interval and responses could occur during it, so the obtained delays were often shorter than the scheduled delay. When the delay occurred after the initial link, initial-link response rates decreased by an average of 77% with no systematic change in response rates in the second or third links. Response rates in the second link decreased an average of 59% when the delay followed that link, again with little effect on response rates in the first or third links. Because the effect of delaying stimulus change was comparable to the effect of delaying primary reinforcement in a simple variable-interval schedule, and the effect of the unsignaled delay was specific to the link in which the delay occurred, the results provide strong evidence for the concept of conditioned reinforcement.     

Spiritual issues in mental health care

Religious and spiritual issues in mental health are explored in the context of four conceptual models: the medical, the nursing, the humanistic, and the pastoral. This is done by looking at each model in terms of content, diagnostic focus, language and treatment goals, and primary qualities in the health provider.The models are illustrated by case studies gathered from a multidisciplinary setting. The discovery that each model can incorporate the religious and spiritual dimension in mental health care, but that each model does this in distinctive ways, is a key point.     

Physicians and clergy in dialogue

The goals and ends of contemporary medicine are often unclear. An explicit inquiry into the religious dimensions of healing offers an important perspective from which to evaluate the potential capabilities of the medical profession. This paper describes a course in which medical students joined divinity students to explore areas of mutual intellectual, professional, and personal interest. Students and faculty examined in depth three broad areas in which medicine and religion share common ground: concepts of health and illness from the religious perspective, approaches to the understanding of suffering and meaning, and the shared professional stresses of physician and clergy.This paper comes from the Department of Medicine, Beth Israel Hospital, and the Division on Aging and the Program for the Analysis of Clinical Strategies, Harvard Medical School, and the West Roxbury-Brockton Veterans Administration Geriatric Research, Education and Clinical Center, Boston.     

The prediction of drug use among college students from MMPI, MCMI, and sensation seeking scales

This study examines the ability of five self-report assessment measures to predict college students' drug use across 12 pharmacological drug categories. Subjects were 125 female and 61 male university undergraduate students. The test battery included the following instruments: the Psychopathic Deviancy (Pd) scale of the Minnesota Multiphasic Personality Inventory (MMPI); the MacAndrew Alcoholism scale (MAC), a special scale of the MMPI; the Sensation Seeking Scale (SSS); the Millon Alcohol Abuse Scale; and the Millon Drug Abuse Scale. Scores from these instruments were utilized in linear combinations to predict individual drug use outcomes as well as polydrug versus single drug use patterns. The drug categories included in this investigation are coffee, tobacco, alcohol, marijuana, tranquilizers, depressants, amphetamines, LSD, other hallucinogens, solvents, narcotics, and cocaine. Results demonstrate significant and meaningful relationships between predictors and drug use levels among college students. Weighted equations derived from linear discriminant function analyses were generally capable of accurately classifying subject's drug use levels across drug categories and in discriminating single drug use from polydrug use patterns. Typically, the Sensation Seeking Scale entered as the most powerful predictor of substance use and abuse.     

Delayed temporal discrimination in pigeons: A comparison of two procedures

A within-subjects comparison was made of pigeons' performance on two temporal discrimination procedures that were signaled by differently colored keylight samples. During stimulus trials, a peck on the key displaying a slanted line was reinforced following short keylight samples, and a peck on the key displaying a horizontal line was reinforced following long keylight samples, regardless of the location of the stimuli on those two choice keys. During position trials, a peck on the left key was reinforced following short keylight samples and a peck on the right key was reinforced following long keylight samples, regardless of which line stimulus appeared on the correct key. Thus, on stimulus trials, the correct choice key could not be discriminated prior to the presentation of the test stimuli, whereas on position trials, the correct choice key could be discriminated during the presentation of the sample stimulus. During Phase 1, with a 0-s delay between sample and choice stimuli, discrimination learning was faster on position trials than on stimulus trials for all 4 birds. During Phase 2, 0-, 0.5-, and 1.0-s delays produced differential loss of stimulus control under the two tasks for 2 birds. Response patterns during the delay intervals provided some evidence for differential mediation of the two delayed discriminations. These between-task differences suggest that the same processes may not mediate performance in each.