Can rats acquire an olfactory learning set?

Experimental rats were trained on multiple 2-odor discrimination tasks, whereas controls were given repeated sessions on Task 1 and then were tested on a novel 2-odor task. Experimental rats showed strong positive transfer across problems and approached errorless or near-errorless learning. Control rats maintained near-perfect performance on Task 1 but performed at chance on initial trials when tested with novel odors. Thus, the near-errorless terminal performance of experimental rats was a function their having been trained on multiple problems and was not simply the result of eliminating "disruptive response tendencies" (I. C. Reid & R. G. M. Morris, 1992). Results support the view that when rats are trained on a series of 2-odor discrimination tasks, they acquire a strategy or rule that allows them to solve new problems with few or no errors.     

Mental Health and Managed Care

In this essay I continue the conversation going on today on the crisis in delivering mental-health care within the realities of managed care. A guiding perspective is represented briefly in material from the writings of Edmund Pellegrino. He recommends the norm of patient-centered relationships to direct and govern managed care so cost can be controlled, but not by the sacrifice of quality of care. This emphasis must be balanced with a struggle for the greater social good and fair allocation of goods to all citizens. Definitions are offered along with a discussion of controversial issues and constructive suggestions to make possible a better future for the work of mental health in relation to managed care.     

A Public Religion and Biomedical Ethics

This article describes the exclusion of public expressions of religion from the history of bioethics during recent decades. It offers a proposal to include public religion for the purpose of gaining donations of vital organs for transplantation, more appreciation for the gift of aging, and more concern for universal access to health care. I also include a brief discussion of theological support and practical suggestions for such a program.     

Effects of different delay of reinforcement procedures on variable-interval responding

Two experiments studied responding in the rat when the first bar press after a variable period of time produced a cue light that remained on for either 10, 30, or 100 sec and terminated with the delivery of food. In Experiment I, response rate decreased and time to the first response after reinforcement increased as the delay of reinforcement increased. Similar results were obtained whether the delay consisted of retracting the lever during the delay, a fixed delay with no scheduled consequence for responding, or every response during the delay restarted the delay interval. In Experiment II, fixed-delay and fixed-interval schedules of the same duration during the delay period had no differential effect on either response rate or time to the first response after reinforcement, but differentially controlled responding during the delay periods.     

Religion,medical ethics,and transplants

This article describes the exclusion of public expressions of religion from the history of bioethics during recent decades. It offers a proposal to include the public church for the purpose of gaining donations of vital organs for transplantation. I also include a brief discussion of theological support and practical suggestions for such a program.     

The Pastor and Bioethics

This essay presents bioethics or ethics in health care as a challenge to pastors. Common professional struggles are experienced by pastoral and health professionals. Thus, first, we need to consider the meaning of being a professional especially as pastors. Second, pastors might explore at least four specific medical issues: namely physician-assisted death or euthanasia, complementary or alternative treatments, the exercise of consent to medical procedures by patients or parishioners and families, and the crucial need for the donation of vital organs to save lives. Embedded within all four issues, there is a significant religious concern which requires the pastor's expertise.     

Effects of conditioned reinforcement frequency in an intermittent free-feeding situation,

Key-pecking intermittently produced a set of brief exteroceptive stimulus changes under two-component multiple schedules of conditioned reinforcement. Throughout the study, free access to grain was concurrently provided on an intermittent basis via a variable-interval tape. Free food presentations scheduled by the tape were delivered if no peck had been emitted for 6 sec, and the brief stimulus changes produced by responding under the multiple schedules were those which accompanied food presentation. The second component of each multiple schedule was always associated with a 1-min, variable-interval schedule of conditioned reinforcement. The schedule associated with the first component was systematically varied and conditioned reinforcement was either absent (extinction) or programmed on a 1-, 3-, 6-, or 12-min variable-interval schedule. Under these conditions, rate of responding in the manipulated component decreased monotonically with a decrease in the frequency of conditioned reinforcement. In addition, contrast effects were often obtained in the constant, second component. These results are similar to those obtained with similar multiple schedules of primary reinforcement.