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841.
The caudal portion of the hypoglossal nucleus (nXIIts) contains the motor neurons that control the syrinx in songbirds. In canaries, song occurs seasonally, is principally produced by males, and appears to be produced predominantly by muscles on the left side of the syrinx. The present study measures the effect of seasonal change and manipulation of testosterone levels on synapse number and morphology in nXIIts in adult female canaries. We find that synapse density is lower in testosterone-treated birds than in control birds and lower in fall than in spring. The number of vesicles per presynaptic profile increases in the spring as a result of a general increase in this measure in all synapses. The number of vesicles per presynaptic profile also increases with testosterone treatment, primarily due to an increase in the proportion of synapses associated with unusually high vesicle counts. Together, these changes suggest that large reserves of neurotransmitter may be necessary to sustain singing. Several ultrastructural differences between hemispheres are found. Postsynaptic thickenings are longer, and postsynaptic processes are larger on the left side than on the right side. In the spring, there are more vesicles per synapse on the left than on the right, but this lateralization is reversed in the fall. Thus, lateralization of song production is associated with lateral asymmetries in synapse morphology. These hemispheric differences are relatively small, like those seen at the light microscope level, encouraging further consideration of peripheral as well as CNS sources of functional lateralization. The seasonal and testosterone-induced changes in synapse number and morphology may be components of the periodic reorganization of canary vocalization. 相似文献
842.
Two experiments were conducted to examine the hypothesized differential effectiveness of two attentional focusing strategies in pain perception. In the first experiment, subjects (72 male college students) rated their levels of pain after being exposed to either low- or high-intensity pressure stimulation for 75 s. Subjects were instructed to use either an external or internal focus of attention during the pain induction. Results revealed that external focusing was more effective for coping than internal focusing across both levels of stimulus intensity. The second experiment was a replication of the first, and featured bolstered internal focusing and stimulus intensity manipulations. Results showed that high-intensity stimulation produced higher pain ratings than did low-intensity stimulation for subjects in the internal focusing conditions, but not for those in the external focusing conditions. The findings support the power of distraction strategies for dealing with short-term pain with a rapid onset. Theoretical implications are discussed.The authors thank Darwyn E. Linder and Daniel M. Landers for their help in development of this research. The authors are also indebted to Sarah Colley, Jona Davis, Nanci Neuberger, and Rebecca Roberts for their assistance in data collection. 相似文献
843.
A number of studies have demonstrated stable individual differences in the cues that generate emotions and other feeling states. These differences are assumed to arise from the cues parents use to identify their children's emotional states. As children learn about their own emotional states, they come to rely on these same cues. To test one implication of their view, the facial expressions of children (N=41) were manipulated and their feelings assessed. Some children reported emotions consistent with their expressions, while others reported emotions appropriate to the situation. In a separate procedure, their mothers were asked to identify the emotional states of children whose expressions were inconsistent with an account of their circumstances. Mothers who paid more attention to their children's expressive behavior had children who were more responsive to their own expressive behavior. In contrast, the mothers who were more responsive to situational cues had children whose emotions arose from the situational cues as well.The authors would like to thank numerous teachers and administrators of the Worcester Public School system in Worcester, Massachusetts, for their assistance. 相似文献
844.
Varieties of size-specific visual selection 总被引:1,自引:0,他引:1
Compared time to evaluate stimuli of varying sizes. When Ss expect an upcoming stimulus to be a certain size, response time increases with the disparity between expected and actual size. There are, however, 2 size adjustment processes, and they reflect 2 types of visual selection. In the first, a shape-specific image representation is used to separate a visual object from a superimposed distractor. These representations require the type of slow size scaling demonstrated in imagery experiments. The second size scaling process is faster and not shape-specific. At any given time the visual system is set to process information at a particular scale, and that scale can be adjusted to match an object's size. Because both selection mechanisms depend on size, they probably occur at a relatively low, spatially organized processing level. These findings lead to a new explanation for results that had been taken as evidence for attentional selection at the level of object representations. 相似文献
845.
HARRY S. BROUDY 《Counseling and values》1989,33(2):83-91
This article is an examination of the political (public consensus) and nonpolitical authority as a basis for values education in a democratic society. The author advocates that nonpolitical authority can be a basis for defending the teaching of values in public schools. 相似文献
846.
Mental health values consist of the subset of values that refer to what constitutes good mental health. Torrey (1972) suggested that agreement between patient and therapist about such values may influence psychotherapy outcome. The authors found mixed support for this hypothesis using a sample of 100 chemical dependency inpatients. Positive treatment effects were associated with pretreatment agreement between counselor and patient about some mental health values, but with pretreatment disagreement about others. Because outcome measures assess general personality functioning, the authors suggest that attitudes about what constitutes good mental health may predict general psychotherapy effects as well as response to alcoholism treatment. 相似文献
847.
ALAN L. LOCKWOOD 《Counseling and values》1989,34(1):3-11
Members of the New Right regularly charge that public schools teach secular humanism. This alleged teaching of secular humanism is held responsible for varied social ills and is perceived as a violation of constitutional prohibitions against the advocacy of one set of religious beliefs over others. Although New Right attacks may be perceived as political tactics, the author explores them as empirical claims that schools are in fact teaching secular humanism. Currently, there is no persuasive body of research supporting the New Right allegations. The author questions whether or not such research could be designed and concludes that it could but, for various reasons, is unlikely ever to be enacted. 相似文献
848.
VIRGINIA M. SPIEGEL 《Counseling and values》1989,34(1):51-56
In this article the author reports results from a national survey of recovering alcoholic Catholic Sisters, describing their addiction history, treatment, and the role of the community. 相似文献
849.
850.
THE RELATIONSHIP BETWEEN RECRUITING SOURCE, APPLICANT QUALITY, AND HIRE PERFORMANCE: AN ANALYSIS BY SEX, ETHNICITY, AND AGE 总被引:2,自引:0,他引:2
This study investigated both an applicant pool and its resulting class of new hires in an attempt to clarify a number of empirical questions concerning recruiting source effectiveness. A pre-established database of applicants and hires for the job of life insurance agent in a large insurance company was analyzed for recruiting activity. Differences in applicant quality and new hire survival were found in favor of the informal recruiting sources. A second measure of hire success, new business commission credits, failed to show differences across recruiting sources. The informal recruiting sources yielded significantly higher selection ratios than did formal sources for all groups. Examination of recruiting source use showed significant group differences, with females and blacks using the formal recruiting sources more frequently than males, non-minorities, and Hispanics. While the informal recruiting sources yielded higher quality applicants and more successful hires for all groups, this research cautions that the implementation of revised recruiting policies must be carefully monitored for adverse effects on protected groups. 相似文献