The effect of reinforcement magnitude upon responding under fixed-ratio schedules

Responding under fixed-ratio schedules was studied as a function of two durations of food presentation. Latency of the first response after food presentation (post-reinforcement pause) was consistently shorter when food was presented for the longer duration. Only one of the four pigeons studied showed a consistently higher response rate, exclusive of post-reinforcement pause, as a function of the longer access to food. When ratio size was reduced, pause durations decreased, and the differences related to the two durations of food presentations became progressively smaller.     

The prefrontal-thalamic axis and classical conditioning

Using the New Zealand albino rabbit as an animal model, it has been determined that the medial prefrontal cortex is intimately involved in, and may be necessary for, acquisition of classically conditioned bradycardia. The interconnected nuclei of the medial thalamus, most notably the mediodorsal nucleus, conversely appear to be associated with the development of the tachycardia that accompanies classical conditioning of the eyeblink and nictitating membrane response. Neuroanatomical, electrophysiological, brain stimulation, and lesion data are reviewed, which support the conclusion that the prefrontal-thalamic axis is intimately involved in acquisition of classically conditioned visceral changes.     

The Society for Research in Child and Adolescent Psychopathology

The Society for Research in Child and Adolescent Psychopathology     

Commentary on "Sedation before ventilator withdrawal

In any important article in the field of clinical ethics, the focus should not be on the specific case example, but rather on the issues it presents for thought and discussion. Barbara Springer Edwards and Winston M. Ueno achieve this end admirably. They present a terminally ill patient who requested termination of ventilator support, despite the overwhelming odds that he would die as a result. The authors ask whether or not the physician acted appropriately in accommodating the patient's wish and in sedating him to decrease suffering in his last moments. They present compelling arguments that sedation was warranted in this case. They also note correctly that competent patients have the right to refuse treatment. However, in addition to the question of sedation, this case raises other important issues, specifically those related to pain management and depression in the terminally ill....     

If “good managers” are masculine,what are “bad managers”?

Little research has been conducted on ineffective behavior or bad characteristics of managers as contrasted with effective behavior or good characteristics. This study examines the perceived characteristics of bad managers as well as good managers. In contrast to a stereotypical view of the good manager as masculine, bad managers were seen by business students as low in both masculinity and femininity, or in nonstereotypical terms. Results were not affected by the relative social desirability of masculine and feminine characteristics.This study was supported by a grant from the University of Connecticut Research Foundation. An earlier version of the article was presented at the 11th Annual Meeting of the American Institute for Decision Sciences, New Orleans, November 1979.     

Individual differences in working memory and reasoning-remembering relationships in solving class-inclusion problems

In the present experiment, we evaluated the effects of individual differences in reading span and variation in memory demands on class-inclusion performance. One hundred twenty college students whose reading spans ranged from low to medium to high (as indexed by a computerized version of the Daneman and Carpenter [1980] reading-span task) solved 48 class-inclusion problems. Half of the subjects had the solution information available when the problems were presented; the other half performed a detection task between solution information and problem presentation. The results from both standard statistical analyses and from a mathematical model indicated that differences in reading span and memory load had predictable, similar effects. Specifically, the sophistication of reasoning strategies declined when memory demands increased or when reading spans decreased. Surprisingly, these effects were primarily additive. The results were interpreted in terms of global resource models and findings from the developmental literature.     

A rat chamber and electrode procedure for avoidance conditioning

A method was developed for studying the reactions of rats to aversive shock. The distinctive features were the design of the chamber and a method of restraint that allowed the use of surface electrodes to deliver the shock. Advantages of this method were: (1) accurate specification of the shock actually received by the rat; (2) elimination of all unauthorized escape or avoidance reactions; (3) elimination of the shock scramblers and floor grids required with foot-shock; and, (4) rapid acquisition of performance under various avoidance procedures and various frequencies of shock delivery.