Response acquisition by Siamese fighting fish (Betta splendens) with delayed visual reinforcement

Male Siamese fighting fish, Betta splendens, swam through a ring in an aquarium, breaking a photocell beam and initiating an unsignaled, resetting delay interval. Following delays of 0 s, 10 s, or 25 s, a 15-s mirror presentation released an aggressive display by the fish. Swimming through the ring increased in the absence of either a period of acclimatization to the reinforcer (analogous to magazine training when appetitive reinforcers are used) or explicit training of the response by the experimenters. Response rates were a decreasing function of delay duration. Other fish exposed to a schedule of response-independent mirror presentations failed to acquire and maintain the response. The results demonstrate the robustness and generality of the phenomenon of response acquisition with delayed reinforcement. They further qualify earlier observations about behavioral mechanisms involved in the phenomenon.     

SEQUENTIAL APPLICATION OF MAJOR HABIT-REVERSAL COMPONENTS TO TREAT MOTOR TICS IN CHILDREN

In this study, we sequentially administered up to four components of the habit-reversal treatment to 4 children with motor tics within a multiple baseline design. The habit-reversal components included (a) awareness training; (b) awareness training and self-monitoring; (c) awareness training, self-monitoring, and social support; and (d) awareness training, social support, and the use of a competing response. Results demonstrated that the combined use of awareness training, social support, and competing response training was effective in eliminating motor tics in 2 of 4 children, that awareness training alone was effective for 1 child, and that a combination of awareness training and self-monitoring was effective for the 4th child. The treatment and ensuing improvement were found to be socially valid. We discuss possible explanations for these results and recommend directions for future research.     

Human Signal-detection Performance: Effects Of Signal Presentation Probabilities And Reinforcer Distributions

University students participated in one of four standard two-choice signal-detection experiments in which signal presentation probability was varied and the reinforcement distribution was held constant and equal. In Experiments 1, 3 and 4, subjects' performance showed a systematic response bias for reporting the stimulus presented least often. Experiments 1 and 4 showed that this effect was reliable with extended training and monetary, rather than point, reinforcement. In Experiment 2, all correct responses were signaled in some way, and this produced the opposite relationship between signal presentation probability and response bias. Experiments 1 and 3 found that explicitly deducting money (intended as punishment) for equal numbers of incorrect responses on each alternative, or varying the obtained overall rate of reinforcement, produced no clear change in response bias. The bias, shown by humans, for reporting the stimulus presented least often remains a challenge for theories of stimulus detection.     

AUGMENTING SIMPLIFIED HABIT REVERSAL WITH AN AWARENESS ENHANCEMENT DEVICE: PRELIMINARY FINDINGS

The chronic hair pulling of a 36-year-old woman with moderate mental retardation was initially treated with a simplified habit-reversal (SHR) procedure that consisted of awareness training, competing response training, and social support. When SHR did not produce large and sustained reductions in hair pulling, an awareness enhancement device was added, and it reduced hair pulling to near-zero levels in two settings. The results are discussed, and directions for future research with this device are provided.     

Competing interests: The need to control conflict of interests in biomedical research

Individual and institutional conflict of interests in biomedical research have becomes matters of increasing concern in recent years. In the United States, the growth in relationships — sponsored research agreements, consultancies, memberships on boards, licensing agreements, and equity ownership — between for-profit corporations and research universities and their scientists has made the problem of conflicts, particularly financial conflicts, more acute. Conflicts can interfere with or compromise important principles and obligations of researchers and their institutions, e.g., adherence to accepted research norms, duty of care to patients, and open exchange of information. Disclosure is a key component of a successful conflict policy. Commitments which conflict with a faculty member's primary obligations to teaching, research, administrative responsibilities, or patient care also need attention. Institutional conflict of interests present different problems, some of which are discussed in an analysis of an actual problem posed by two proposed clinical trials. This paper is adapted from a lecture presented to a Symposium on Scientific Integrity, Warsaw, Poland, 23 November 1995. Daniel Steiner was Vice-President and General Counsel of Harvard University (1972–92) and in that capacity became familiar with conflict of interest issues. He is currently Counsel to the Boston law firm. Ropes and Gray, and is Adjunct Lecturer in Public Policy at the John F. Kennedy School of Government. Harvard University.     

影响常用汉字认知速度的因素：低频冲突字、联绵词尾字和高频多音字的认和特点

以汉族大学生为被试对低频冲突字、联绵词尾字和高频多音字的认知特性进行了探索。结果发现：主要部件读音与整字读音相冲突的低频字命名反应中具有延时效应（即命名反应时延长或反应错误率升高）;对联绵词尾字和多音字的命名反应同样出现延时效应。研究支持汉字认知的多因素影响论。     

Temporal control of behavior: schedule interactions

In Experiment I the response that terminated the postreinforcement pauses occurring under a fixed-interval 60-second schedule was reinforced, if the pause duration exceeded 30 seconds. The percentage of such pauses, rather than increasing, decreased. There were complex effects on the discriminative control of the pause by the reinforcer terminating the previous fixed interval, depending on whether the fixed interval and the added reinforcer were the same or different. In Experiments II(a) and II(b), each reinforcement initiated an alternative fixed-interval interresponse-time-greater-than-t-sec schedule, the schedule values being systematically varied. When the response following a pause exceeding a given duration was reinforced, fewer such pauses occurred than when they were not reinforced, i.e., on the comparable simple fixed-interval schedule. There was no systematic relationship between mean interrinforcement interval and duration of the postreinforcement pause. The pause duration initiated by reinforcement was directly related to the dependency controlling the shortest pause at that time, regardless of changes in mean interreinforcement interval.     

The relative law of effect: effects of shock intensity on response strength in multiple schedules

Key pecking of four birds was reinforced with food according to a two-component multiple variable-interval 1-minute variable-interval 4-minute schedule. In addition, key pecking was punished by a brief shock according to a variable-interval 30-second schedule during both components of the multiple schedule. The intensity of the shock was varied. For all birds, punishment had a stronger suppressive effect on the responding maintained by the leaner food schedule, and the ratio of responding during the two components of the multiple schedule became closer to the ratio of reinforcement as shock intensity was increased, as the relative law of effect predicts. At the higher shock intensity, there was some evidence that the ratio of responses overmatched the ratio of reinforcements.     

Variability of response location on fixed-ratio and fixed-interval schedules of reinforcement

Variability of response location was studied in monkeys performing in a six-lever chamber. Fixed-ratio schedules, ranging from FR 1 to FR 300, generated a high degree of stereotypy of response location. In contrast, fixed-interval schedules of comparable reinforcement frequencies (0.06 to 4 minutes) generated much greater variability. These results failed to confirm any simple relationship between response variability and intermittence of reinforcement. Rather, variability seems to be determined by the particular characteristics of the reinforcement schedule.     

Beyond the relational principle of reinforcement

Behavior under baseline conditions in which the contingency is absent can shed some light on the individual's performance under a schedule, but is insufficient as a basis for prediction of performance. This insufficiency of the baseline data runs counter to a recent formalization of the relational principle of reinforcement (Donahoe, 1977). A more satisfactory predictive model must incorporate not only the baseline level of the instrumental response and that of the contingent response, but also the schedule requirements, the character of each response in relation to the other, and the behavior required in simply switching from each to the other.