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891.
892.
Handling time and choice in pigeons   总被引:2,自引:1,他引:1       下载免费PDF全文
According to optimal foraging theory, animals should prefer food items with the highest ratios of energy intake to handling time. When single items have negligible handling times, one large item should be preferred to a collection of small ones of equivalent total weight. However, when pigeons were offered such a choice on equal concurrent variable-interval schedules in a shuttlebox, they preferred the side offering many small items per reinforcement to that offering one or a few relatively large items. This preference was still evident on concurrent fixed-cumulative-duration schedules in which choosing the alternative with longer handling time substantially lowered the rate of food intake.  相似文献   
893.
Scores on the Beck Depression Inventory (BDI) were periodically obtained from the roommates of college students who exhibited a persistent mild depression over a 3-month period. For comparative purposes, BDI scores were also obtained from roommates of individuals who were transiently depressed and from subjects with nondepressed roommates. In comparison with control subjects, the roommates of persistently depressed persons displayed a progressive increase in BDI score over the course of the study.  相似文献   
894.
895.
896.
The foot is a highly cathected appendage that is commonly singled out as the brunt of humorous or derisive remarks, as if it embodies repugnance and disgust. Attitudes toward the foot are overdetermined, bearing the imprint of man's early linguistic patterns and individual dynamics. This article suggests that feet are symbolic because they bear the feelings derived from earlier separations, good and bad object representations, collective memories, and genital representations. The foot's role as symbol of both the male and female genitals, repository of badness, symbol of passivity, initiator of movement, and site of self-mutilation have been briefly reviewed. As Fats Waller rhapsodizes that the "feet's too big," he finds a convenient way to displace his symbiotic and erotic anxieties vis-à-vis women. Similarly, patients who come for psychiatric treatment and psychotherapy frequently make references to their feet or use them in specific ways. An understanding of this type of communication can often provide insight into individual dynamics and enhance treatment. The weight placed on these communications depends, of course, on the vicissitudes of the previous therapeutic work as well as on the particular problems of the patient.  相似文献   
897.
898.
Gender differences across age in motor performance a meta-analysis   总被引:3,自引:0,他引:3  
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899.
David Harrah 《Synthese》1985,63(3):275-294
In this paper we sketch a logic of message and reply. The logic is intended for application in a wide variety of situations, not restricted to the two-person, turn-taking situation. Each message has a body and a vector; the vector specifies the from, to, and the like. To reply to a message, it suffices to give either (1) a complete reply to the body or (2) a corrective reply to at least one presumption derivable from the vector. We discuss the problems of achieving effectiveness and completeness with respect to certain aspects of communication. The results are mixed. In section 9 we argue semi-formally that, in a certain sense, dialogue is necessary. Finally we note that this logic is not a rival of other approaches but may be combinable with them.  相似文献   
900.
This paper reports an experiment testing two hypotheses. The first is that the value or utility associated with a payment to one's self and a payment to a co-worker can be represented as an additive function of a utility for own payment (nonsocial utility) and a utility for the difference between own and other's payment (social utility). The second hypothesis is that changes in the amount of work accomplished by one's self and/or the other should influence the social, but not the the nonsocial utilities. Support for both hypotheses is reported.  相似文献   
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