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161.
Typical delay determines waiting time on periodic-food schedules: Static and dynamic tests 总被引:6,自引:6,他引:0 下载免费PDF全文
Pigeons and other animals soon learn to wait (pause) after food delivery on periodic-food schedules before resuming the food-rewarded response. Under most conditions the steady-state duration of the average waiting time, t, is a linear function of the typical interfood interval. We describe three experiments designed to explore the limits of this process. In all experiments, t was associated with one key color and the subsequent food delay, T, with another. In the first experiment, we compared the relation between t (waiting time) and T (food delay) under two conditions: when T was held constant, and when T was an inverse function of t. The pigeons could maximize the rate of food delivery under the first condition by setting t to a consistently short value; optimal behavior under the second condition required a linear relation with unit slope between t and T. Despite this difference in optimal policy, the pigeons in both cases showed the same linear relation, with slope less than one, between t and T. This result was confirmed in a second parametric experiment that added a third condition, in which T + t was held constant. Linear waiting appears to be an obligatory rule for pigeons. In a third experiment we arranged for a multiplicative relation between t and T (positive feedback), and produced either very short or very long waiting times as predicted by a quasi-dynamic model in which waiting time is strongly determined by the just-preceding food delay. 相似文献
162.
Body-frame size is an important factor in determining an optimal body weight for a given height. Previous studies have indicated that many individuals incorrectly estimate their body-frame size, and, as a result, incorrectly assess their ideal weight. The present study investigated the accuracy of estimation of body-frame size as a function of sex and actual frame size. The subjects were 66 men and 52 women participating in a community adult fitness program. Data indicated that medium-framed individuals were the most accurate in their estimations of body-frame size. Also, women were twice as likely to be accurate as were men. These results are interpreted to mean that most people assume they are medium-framed and that there is a sex difference in the way body-frame size is estimated. 相似文献
163.
Light-eyed individuals generally perform better at self-paced activities while dark-eyed individuals perform better at reactive activities. Using multiple regression it was found that dark-eyed students hit a target with a frisbee more times than did light-eyed students. 相似文献
164.
Fixation accuracy was related to perception of laterally presented consonants. Small left-eye fixation inaccuracy influenced perceptual performance of 8 men and 8 women. 相似文献
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Visual cognitive differences between hearing (N = 16) and deaf (N = 32) high-school and middle-school students were studied. Visual tasks were presented on a microcomputer and response latencies were collected. Significant differences were noted between the deaf and normal groups but not between total communication deaf and oral deaf students. These differences support the hypothesis that deaf students prefer a visual cognitive strategy. Implications for educating the deaf are discussed. 相似文献
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