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911.
Pigeons responded in a two-key situation. Responses on the right key (food key) were reinforced with food presentation on a response-initiated fixed-interval schedule, (i.e., first response after a fixed period of time was reinforced); responses on the left key (target key) were reinforced on a fixed-ratio schedule (i.e., every nth response was reinforced) with the presentation of a target bird that could be attacked. When the interval value of the food reinforcement schedule was varied from 1 min to 5 min, both the rate of attack responding on the target bird and the rate of responding on the target key were a function of the interval value. Responding on the target key was not maintained by the stimulus change associated with target availability, and was successively extinguished and reconditioned by removing and returning the target bird to the restraining box. When food was delivered independently of behavior, responding on the target key either remained unchanged or decreased, but was not eliminated. Responding on the target key was not maintained in the absence of an intermittent schedule of food presentation.  相似文献   
912.
913.
914.
Rats were taught to bar press for food in a Skinner box. The amount of time needed to make 10 bar presses increased significantly after a bar press was accompanied by an air blast and loud tone. This increase did not occur if the air blast and tone were followed 8 sec later by an ECS. The technique is simple and effective, and preserves the previously established effects of ECS on recent memory. Hopefully it will prove useful in situations where the investigator wishes to establish a one-trial passive avoidance without the use of painful shock.  相似文献   
915.
Explored the ecological consequences of crime and violence. Selected to reflect alienation between individuals and their settings, the criterion measures were fear of crime, avoidance behavior, anomia, and external locus of control. Exposure to crime was assessed at both individual and community levels. Using data from a large statewide sample of adult Kentuckians, hierarchical regression analyses were performed in which the criterion variables were regressed on measures of social status (e.g., education, sex), crime, and interactions between the two. The pattern of results highlighted the pervasive consequences of experiencing personal violence; effects of property crime and community-level exposure were more limited in scope. Social status also exerted strong effects on the criterion measures and modified many of the observed effects of crime. Implications of the study for interventions are discussed.  相似文献   
916.
Helplessness deficits in students: The role of motivational orientation   总被引:3,自引:0,他引:3  
This paper includes research comprised of field studies and laboratory experiments to examine our diathesis-stress model that students with an extrinsic motivational orientation given evaluative/controlling directives are at risk for maladaptive achievement patterns, including performance, cognitive, and emotional deficits of helplessness. The findings, using our multimethod approach, confirmed our assumptions and indicated that motivational orientation is a more reliable predictor of helplessness than either attributions or perceptions of competence. The pattern of data obtained across studies is discussed in light of other theoretical approaches to understanding achievement patterns in students.The research reported here was supported, in part, by Grant No. MN45566 from NIMH. Address all correspondence to Ann K. Boggiano, Department of Psychology, Campus Box 345, University of Colorado, Boulder, Colorado 80309-0345.  相似文献   
917.
Summary In a probe-tone experiment, two groups of listeners — one trained, the other untrained, in traditional music theory — rated the goodness of fit of each of the 12 notes of the chromatic scale to four-voice harmonic sequences. Sequences were 12 simplified excerpts from Bach chorales, 4 nonmodulating, and 8 modulating. Modulations occurred either one or two steps in either the clockwise or the counterclockwise direction on the cycle of fifths. A consistent pattern of probe-tone ratings was obtained for each sequence, with no significant differences between listener groups. Two methods of analysis (Fourier analysis and regression analysis) revealed a directional asymmetry in the perceived key movement conveyed by modulating sequences. For a given modulation distance, modulations in the counterclockwise direction effected a clearer shift in tonal organization toward the final key than did clockwise modulations. The nature of the directional asymmetry was consistent with results reported for identification and rating of key change in the sequences (Thompson & Cuddy, 1989 a). Further, according to the multiple-regression analysis, probe-tone ratings did not merely reflect the distribution of tones in the sequence. Rather, ratings were sensitive to the temporal structure of the tonal organization in the sequence.  相似文献   
918.
Summary Subjects performed a timed-response task in which they attempted to synchronize a rapid flexion of the index finger of their preferred hand with the last of a train of four regularly spaced acoustic clicks. The task was used to stabilize the execution time of a simple voluntary response in order to facilitate psychophysical judgments about the subjects' perception of having responded and of having intended to respond. In the first experiment, male subjects (N = 6) adjusted the appearance time of a reference stimulus (a brief percutaneous pulse to the responding finger) until it appeared to be simultaneous with their perception of having made the response. All subjects adjusted the reference stimulus to appear after response onset during the latter half of the force impulse. This finding suggests that the perception of having responded is based on peripheral feedback from the response. In the second experiment, male subjects (N = 6) performed the same motor task, but adjusted the time of the reference stimulus so that it appeared to be simultaneous with their intention to respond. Two subjects were not able to do the task successfully; the remaining four subjects adjusted the reference stimulus to appear from 101 to 145 ms before response onset. This finding suggests that the intention to respond is perceptually separable from the response itself and occurs at a measurable time before response onset.  相似文献   
919.
The rationale and problems encountered in implementing a peer-support telephone intervention are described. The research conducted by Heller, Thompson, Trueba, Hogg, and Vlachos-Weber (1991) was based on epidemiological literature documenting the moral enhancing value of confidante relationships. However, that literature may be insufficiently precise to form the basis for an intervention without prior ethnographic study of the local target population. Furthermore, the positive effects of peer friendships may refer to long established relationships rather than to newly formed social ties. It is concluded that future support intervention research with older adults should concentrate on reinforcing meaningful role activities, and that greater attention should be given to strengthening indigenous ties before attempting to create new ones. While prior process research and formative evaluation are of value, we also emphasize the importance of well-controlled field studies in the ultimate test of intervention hypotheses.  相似文献   
920.
Female-female interactions and social stress in prairie voles   总被引:1,自引:0,他引:1  
Trios of prairie voles (Microtus ochrogaster) composed of either two estrous sibling or nonsibling females and one male were monitored via time-lapse videotaping over 72 hr. Social and sexual behaviors were analyzed as a function of trio type (sibling or nonsibling) and fate (survivor or nonsurvivor) across 12-h time blocks. Within nonsibling trios, females that were able to maintain prolonged physical contact with the male within the first 3 days of trio formation later survived and successfully produced litters; females that did not maintain male contact later died of undetermined causes, presumably related to social stress. Frequencies of sexual behavior were similar in both trio types and both surviving and nonsurviving females received equivalent amounts of copulatory stimulation from the male. Sibling groups exhibited higher levels of female-female side-by-side contact; nonsibling groups exhibited greater amounts of female-initiated anogenital sniffing, and female-initiated aggression. Female-female social interactions may be determined by prior familiarity and/or relatedness and may play a dominant role in determining the social organization and mating system of this species.  相似文献   
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