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41.
Regional cerebral blood flow (rCBF) may be measured with inhalation techniques that use end-expired values of radioactivity to estimate the isotope concentration in arterial blood. These end-expired data are used as an input function in a mathematical equation to derive rCBF. End-expired air is assumed normally to be in equilibrium with the arterial blood at the alveolar surface of the lung during regular (passive) breathing; this assumption may not be valid during continuous phonation. We therefore have analyzed breathing (inhalation/exhalation) patterns and end-expired radioactivity (133Xe) during (1) speaking, (2) singing, and (3) humming of the national anthem, and also during (4) passive breathing. Statistically significant differences in breathing patterns were measured between a group of nonmusicians and two groups of musicians (singers) during the phonation tasks: The nonmusicians breathed more often (and more rapidly) and exhibited less variability in their breathing patterns than did the musicians. Notwithstanding these differences, the shapes of smoothed functions derived from the end-expired values were not influenced appreciably during phonation (except possibly during talking). The latter finding suggests that estimates of rCBF derived with these data should not be confounded seriously because of the continuous phonation.  相似文献   
42.
Higher levels of affiliation motivation after exposure to affiliative films are significantly related to higher dopamine concentrations in saliva in one study of 61 college students of both sexes, and in plasma in another study of 47 adults of both sexes. Individuals high in dispositionaln Affiliation, if they also reported high life stress, showed high gains in dopamine concentration in plasma after exposure to an affiliative film significantly more often than other individuals. Since aroused affiliation motivation was not associated with higher concentrations of norepinephrine, epinephrine, or cortisol in either study, it appears likely that dopamine is especially associated with arousal of affiliation motivation, just as norepinephrine has been found to be associated with arousal of power motivation. Thus, different motives may be subserved by different hormones, making it unlikely that all motives lead to the same state of physiological arousal.This research was carried out when all the authors were connected with the Department of Psychology and Social Relations at Harvard University. We acknowledge with thanks the support of the John D. and Catherine T. MacArthur Foundation through a grant to the senior author.  相似文献   
43.
Operant conditioning and multidimensional scaling procedures were used to study auditory perception of complex sounds in the budgerigar. In a same-different discrimination task, budgerigars learned to discriminate among natural vocal signals. Multidimensional scaling procedures were used to arrange these complex acoustic stimuli in a two-dimensional space reflecting perceptual organization. Results show that budgerigars group vocal stimuli according to functional and acoustical categories. Studies with only contact calls show that birds also make within-category discriminations. The acoustic cues in contact calls most salient to budgerigars appear to be quite complex. There is a suggestion that the sex of the signaler may also be encoded in these calls. The results from budgerigars were compared with the results from humans tested on some of the same sets of complex sounds.  相似文献   
44.
To evaluate expectations derived from ego-identity theory and symbolic-interaction theories about the association between self-concept and peer-group affiliations in adolescence, we examined the self-esteem of 221 7th through 12th graders associated by peers with one of five major school crowds and 106 students relatively unknown by classmates and not associated with any school crowd. Among crowd members, self-esteem was directly related to the position of one's crowd in the peer-group status hierarchy (based on both peer-rated and self-perceived crowd affiliation). Outsiders' self-esteem differed in relation to the accuracy of their reflected appraisal of and the salience they attached to crowd affiliation. Crowd members as a whole exhibited higher self-esteem than outsiders as a whole. Differences, however, were mediated by crowd status, salience of crowd affiliation, and the accuracy of reflected appraisals. An adequate interpretation of the findings required an integration of Festinger's (1954, 1957) social comparisons and cognitive-dissonance theories, Cooley's (1902) notions of reflected appraisal, and Newman and Newman's (1976) extrapolations from ego-identity theory.  相似文献   
45.
A major home improvement chain located primarily in the western United States initiated the use of thePersonnel Selection Inventory, a written integrity test, as part of its pre-employment hiring process. For two years only, those job applicants who passed this test and other pre-employment criteria were hired by the chain. Following the introduction of the inventory, there was: (1) a 50% reduction in the number of employee terminations for theft, illegal drug use, and violence over a five year period and (2) a savings in shrinkage losses that amounted to over two million dollars over a two year period.  相似文献   
46.
Children aged 1.5 to 8 years were required to touch accurately an illuminated target lamp located on a vertical board. Movements were made when visual information was complete (target lit for 3 s, room illuminated; partial (target lit for 3 s, room dark, and reduced (target lit for 0.7 s, room dark). Dependent variables were response accuracy, reaction time, and movement time. Accuracy decreased with decreasing availability of visual information and improved with age under all conditions. Reaction times were shorter in the dark (Conditions 2 and 3) than in the light; they decreased with age up to age 5 and did not continue to decrease thereafter. Movement time did not change with age under Conditions 1 and 3 but tended to increase with age under Condition 2. Slower movements were more accurate at all ages, provided visual feedback could be utilized. Increased reliance on the strategy "slower movements yield higher accuracy" was held to account for developmental changes under Condition 2, whereas in Conditions 1 and 3 improvement in the efficiency of motor preprogramming was implicated.  相似文献   
47.
This article acknowledging and celebrating William Barr Oglesby, Jr. as Pastoral Theologian of the Year for 1983, was originally published inPastoral Psychology 32(1) in Fall, 1983. As a result of some errors that inadvertently modified both the tone and the meaning of the text, we are republishing this article here in its entirety.  相似文献   
48.
Tachistoscopic presentation of light flashes was used to test for differences in visual sensitivity among 3 groups of practitioners of Buddhist mindfulness meditation and non-meditator-controls. Meditation practitioners were able to detect light flashes of shorter duration than the non-meditators. There were no differences among the meditator groups. There were no differences among the groups in ability to discriminate between closely spaced successive light flashes. The lower detection threshold for single light flashes for the meditators may reflect an enduring increase in sensitivity, perhaps the long-term effects of the practice of mindfulness meditation on certain perceptual habit patterns. The lack of significant differences in the discrimination of successive light flashes probably reflects the resistance of other perceptual habit patterns to modification. The results support the statements found in Buddhist texts on meditation concerning the changes in perception encountered during the practice of mindfulness.  相似文献   
49.
This experiment represented an initial at tempt at comparing same-different classifications and similarity judgments of Markov histoforms sampled from three different schema families. A measure of individual stimulus variability was more strongfy related to classification responses than to judged similarity. Dichotomous responses, derived from the similarity data by imposing threshold criteria, were found to be highly similor to real classification responses when the threshold values were estimated directly from the latter; little correspondence, however, was obtained using optimal classification criteria. The results support the notion that somewhat different features are used in making classification responses and similarity judgments, and indicate the need for developing more sensitive tasks involving controlled scanning of pattem information.  相似文献   
50.
Intermodal perceptual equivaience was investigated, using visual and tactual oddity discrimination and cross-modal matching-to-sample tasks. Four groups of Ss were presented with 100 problems made up of randomly derived forms from five levels of sidedness. The same quadratic relationship was observed for all tasks as a function of complexity, with optimal performance at eight sides. Comman information utilization, as indicated by intercorrelations of performance variables and by correlational analyses with differences in form measures, was not as pronounced within side classes. Evidence concerning the nature of pattern-feature usage in discrimination was obtained from graphical analyses.  相似文献   
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