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241.
In two experiments, patterns of response error during a timing accuracy task were investigated. In Experiment 1, these patterns were examined across a full range of movement velocities, which provided a test of the hypothesis that as movement velocity increases, constant error (CE) shifts from a negative to a positive response bias, with the zero CE point occurring at approximately 50% of maximum movement velocity (Hancock & Newell, 1985). Additionally, by examining variable error (VE), timing error variability patterns over a full range of movement velocities were established. Subjects (N = 6) performed a series of forearm flexion movements requiring 19 different movement velocities. Results corroborated previous observations that variability of timing error primarily decreased as movement velocity increased from 6 to 42% of maximum velocity. Additionally, CE data across the velocity spectrum did not support the proposed timing error function. In Experiment 2, the effect(s) of responding at 3 movement distances with 6 movement velocities on response timing error were investigated. VE was significantly lower for the 3 high-velocity movements than for the 3 low-velocity movements. Additionally, when MT was mathematically factored out, VE was less at the long movement distance than at the short distance. As in Experiment 1, CE was unaffected by distance or velocity effects and the predicted CE timing error function was not evident. 相似文献
242.
Resistance To Change As A Function Of Stimulus-reinforcer And Location-reinforcer Contingencies 下载免费PDF全文
Pigeons responded on two keys in each component of a multiple concurrent schedule. In one series of conditions the distribution of reinforcers between keys within one component was varied so as to produce changes in ratios of reinforcer totals for key locations when summed across components. In a second series, reinforcer allocation between components was varied so as to produce changes in ratios of reinforcer totals for components, summed across key locations. In each condition, resistance to change was assessed by presenting response-independent reinforcers during intercomponent blackouts and (for the first series) by extinction of responding on both keys in both components. Resistance to change for response totals within a component was always greater for the component with the larger total reinforcer rate. However, resistance to change for response totals at a key location was not a positive function of total reinforcement for pecking that key; indeed, relative resistance to extinction for the two locations showed a weak negative relation to ratios of reinforcer totals for key location. These results confirm the determination of resistance to change by stimulus—reinforcer contingencies. 相似文献
243.
Todorov J 《Journal of the experimental analysis of behavior》1996,66(1):7-9
244.
Within-session Changes In Responding During Concurrent Variable-interval Schedules 总被引:3,自引:3,他引:0 下载免费PDF全文
McSweeney F Weatherly J Swindell S 《Journal of the experimental analysis of behavior》1996,66(1):75-95
Five rats and 4 pigeons responded for food delivered by several concurrent variable-interval schedules. The sum of the rates of reinforcement programmed for the two components varied from 15 to 480 reinforcers per hour in different conditions. Rates of responding usually changed within the experimental session in a similar manner for the two components of each concurrent schedule. The within-session changes were similar to previously reported changes during simple schedules that provided rates of reinforcement equal to the sum of all reinforcers obtained from the concurrent schedules. The number of changeovers also changed within sessions in a manner similar to the changes in instrumental responding. These results suggest that changeovers are governed by the same variables that govern instrumental responding. They also suggest that the within-session change in responding during each component of a concurrent schedule is determined by approximately the sum of the reinforcers obtained from both components when both components provide the same type of reinforcer. 相似文献
245.
In light of information uncovered about human radiation experiments conducted during the Cold War, an important charge for the Advisory Committee on Human Radiation Experiments was to assess the current state of protections for human research subjects. This assessment was designed to enhance the Committee's ability to make informed recommendations for the improvement of future policies and practices for the protection of research subjects. The Committee's examination of current protections revealed great improvement over those from the past, yet some problems remain. Although the data collected by the Committee highlight specific areas in need of attention, the Committee's work should be viewed in part as the beginning of a series of ongoing assessments of the adequacy and effectiveness of the protections afforded to human subjects. 相似文献
246.
对人的尊严的挑战——试论P.辛格的优先权——实利主义 总被引:2,自引:0,他引:2
一个社会对其成员重视和承认的程度,首先表现为这个社会如何对待其成员中的弱者和受歧视的人。而在每个社会遭受歧视的人中,无疑也包括那些由于先天或后天的缘故患有精神上或肉体上的疾病而需要特别照顾的人。1989年以来,首先是这一社会群体的代言人,对他们的遭遇提出了强烈的抗议。而他们的抗议,又引发了德国舆论界对澳大利亚哲学家彼得·辛格的关注。特别是辛格关于可以对残疾人(既包括先天不足的婴儿,也包括老年人)施行强制性安乐死的论述,点燃了论战的烽火,更激起了一部分人的强烈抗议。残疾人的代盲人指出,辛格的“实用伦理学”不仅是对“残疾人”,而且从根本上讲是对人的错误认识。 相似文献
247.
248.
249.
Allison J 《Journal of the experimental analysis of behavior》1978,29(3):557-560
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. 相似文献
250.