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841.
The role of marking when reward is delayed   总被引:1,自引:0,他引:1  
Two-choice spatial discrimination by rats is enhanced if a salient stimulus marker occurs immediately after every choice response and again after a delay interval (Lieberman, McIntosh & Thomas, 1979). Three experiments further explore this effect. Experiment 1 found that the second marker is unnecessary. Experiment 2 found that a marker presented before a response is as effective as one presented after. Both effects could be explained in terms of markers focusing attention on subsequent cues. Experiment 3, however, found that markers after choice enhance learning even when no discriminative cues are present following the marker. Markers thus appear to initiate both a backward search through memory and attention to subsequent events; both processes help to identify events that might be related to the unexpected marking stimulus.  相似文献   
842.
An experiment is reported designed to test the hypothesis that female rats might discriminate between males that differed in the quantity of odor deposited by scent marking. Male odor donors were selected by prior screening for high or low rates of scent marking in an open arena. Females were then tested to determine whether they showed any preference for males that marked at a high rate. It was found that female rats did discriminate, but that they preferred to remain near males selected for low rates of scent marking.  相似文献   
843.
Impaired retention of an inhibitory avoidance response was observed in rats subjected to adrenalectomy (ADX) up to 120 hr before the single learning trial. Corticosterone substitution failed to normalize this behavioral deficit. Rats ADX 240 hr prior to the learning trial showed a normalized behavior. Adrenomedullectomy (ADXM) 48 or 240 hr before learning caused a similar impairment as in short-term ADX rats. The 240-hr ADX rats subjected to corticosterone substitution showed the same behavioral deficit as short-term ADX rats or ADXM ones. Immediate postlearning subcutaneous injection of adrenaline in a dose range of 0.005-5.0 micrograms/kg or of noradrenaline (0.005-0.5 microgram/kg) to 48-hr ADX rats resulted in a dose-related improvement of later retention behavior. Higher doses of catecholamines were less or ineffective. Postlearning treatment of 48-hr ADXM rats with adrenaline (0.5-500 micrograms/kg) caused a similar pattern of behavioral changes. It is concluded that adrenal catecholamines play an important role in the modulation of consolidation of memory. In addition, the high circulating ACTH levels that follow long-term ADX may correct for the behaviorial deficit induced by the absence of adrenomedullary catecholamines.  相似文献   
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845.
Cognitive motivation and drug use: a 9-year longitudinal study.   总被引:2,自引:0,他引:2  
The predictive precedence of expectancy constructs, operationally defined as cognitive motivations, and drug use was investigated over a 9-year period from adolescence to adulthood. Alternative predictions from three different classes of theories of expectancy-behavior relations, including expectancy theory, a Skinnerian approach, and a reciprocal determinism perspective, were evaluated. The results are most consistent with the notion based in expectancy theory that cognitive motivations are nonspurious and possibly functionally autonomous influences on the use and abuse of drugs. More limited support is found for the view that drug use leads to cognitive motivations, as postulated in other theoretical perspectives. Other findings reveal the presence of expectancy generalization processes consistent with Rotter's (1954) expectancy theory, as well as the unique status of cognitive motivations for alcohol as an independent predictor of problem drug use.  相似文献   
846.
Disintegrated experience: the dissociative disorders revisited   总被引:2,自引:0,他引:2  
We present proposed changes to the dissociative disorders section of the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders and review the concept of pathological and nonpathological dissociation, including empirical findings on the relations between trauma and dissociative phenomenology and between dissociation and hypnosis. The most important proposals include the creation of two new diagnostic entities, brief reactive dissociative disorder and transient dissociative disturbance, and the readoption of the criterion of amnesia for a multiple personality disorder diagnosis. We conclude that further work on dissociative processes will provide an important link between clinical and experimental approaches to human cognition, emotion, and personality.  相似文献   
847.
A BASIC program to generate values for variable-interval (VI) schedules of reinforcement is presented. A VI schedule should provide access to reinforcement with a constant probability over a time horizon. If the values in a VI schedule are calculated from an arithmetic progression, the probability of reinforcement is positively correlated with the time since the last reinforcer was delivered. Fleshler and Hoffman (1962) developed an iterative equation to calculate VI schedule values so that the probability of reinforcement remains constant. This easy-to-use program generates VI schedule values according to the Fleshler and Hoffman equation, randomizes the values, and saves the values in ASCII to a disk file.  相似文献   
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