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891.
Preexposure to an unreinforced stimulus facilitates learning (perceptual learning) under some conditions, but it can have the opposite effect (latent inhibition) under other conditions. Researchers have suggested that perceptual learning depends on a change of context, whereas latent inhibition is usually context specific. The associative theory explains both phenomena within a single framework. The authors report 4 experiments that show that perceptual learning does not depend on a context change. The experiments suggest that latent inhibition, unlike perceptual learning, depends on passive exposure. Thus the results do not support the associative theory. They are more consistent with Gibson's stimulus-differentiation theory.  相似文献   
892.
Five mothers of 50 newborn rat pups were maintained on either standard lab chow or a diet composed of the same chow with onion powder added. Taste preference tests administered during weaning indicated that the pups whose mother was fed the onion chow showed a preference for onion diet, but that such preference dissipated across the five day testing period. A control group of pups who were exposed to any onion diet cues available through channels other than the mother's milk did not show a preference for onion diet. It was concluded that exposure to onion taste in mother's milk was responsible for an initial preference for onion diet.  相似文献   
893.
To examine the reciprocal relations between teacher–child relationships and children's behavior problems, the authors analyzed cross-lagged longitudinal data on teacher–child relationships and children's internalizing and externalizing problems using a structural equation modeling approach. The homeroom teachers of 105 first-year preschoolers aged 2–3 years filled in the Student–Teacher Relationship Scale and the Child Behavior Checklist/2–3, first at 3 months after the children's preschool entrance and then at the end of the first preschool year. Results showed significant cross-wave reciprocal relations between externalizing problems and teacher–child conflict and significant cross-wave relation from early internalizing problems to later teacher–child conflict. However, the cross-wave associations between internalizing and externalizing problems and teacher–child closeness were not significant.  相似文献   
894.
The use of visual action feedback (AIF) in learning a simple motor response can sometimes be as effective as the more conventional terminal feedback (TIF) but sometimes leads to gross overshooting errors when AIF is removed. Both the amplitude of movement and the gain of the AIF have strong and systematic effects on the error in attempted reproductions. Percent overestimation increases linearly with fog. gain and decreases linearly with log. amplitude. This may be due to an intersensory effect in which visual and kinesthetic feedback sum to form a unitary impression of the movement on which subsequent attempts at reproduction are based.  相似文献   
895.
This experiment tested the hypothesis that there would be a significant increase in powerlessness scores over a 10 year period. The sample was drawn from a population of college students originally tested in 1964. At the 10 year follow-up, all Ss had graduated from college and were either professionally employed (mostly as teachers) or engaged in child-rearing/home activities. The average age of the 1974 sample was 29 years and consisted of 70 females and 30 males. The test instrument was the adult version of Rotter's Internal-External (I-E) Locus of Control Scale which consists of 23 forced-choice items. There were no significant differences on total I-E scores over the 10 year period. However, with use of the Mirels two-factor scoring system, significant increases in social-political control were found. No significant differences in personal control were found. It was concluded that care should be taken in utilizing cross-sectional findings and that utilizing multidimensional scores suggests different results for previously published reports.  相似文献   
896.
《Developmental Review》2013,33(3):151-167
In this paper we review the evidence linking the early development of the autonomic nervous system in early childhood to four proximal risk factors: maternal stress during pregnancy, maternal substance use during pregnancy, poor-quality parent–child interactions, and specific disruptions in parenting behavior. A clear pattern of altered autonomic function emerges in children exposed to proximal risk, marked by reduced parasympathetic tone under conditions of both homeostasis and challenge, accompanied by increased sympathetic tone in some cases. This pattern of autonomic activity would support increased vigilance and active defense responses, which, in an environment of high proximal risk, may be adaptive in the short-term. However, in the long-term maintaining such a state may impose a high allostatic load. The current paper reviews and interprets the current literature and discusses future directions.  相似文献   
897.
亚健康中抑郁程度人群分布特点的对应分析   总被引:1,自引:0,他引:1  
为了分析亚健康人群抑郁的不同表现程度与不同人口学资料的关系,采用"亚健康状态的测量及诊断标准研究"课题组调查的中国人亚健康资料,利用对应分析对抑郁表现因子总分的不同等级与不同的年龄、婚姻、职业和学历的关系进行分析。结果显示,20岁~30岁、未婚、学生和大专及以上学历主要表现为中重度抑郁倾向,31岁~40岁、已婚、专业人士和高中专学历主要表现为中度抑郁倾向,41岁~60岁、工人、农民和初中以下学历的抑郁倾向较轻,结论为亚健康人群的心理不适,特别是抑郁倾向,主要集中在年龄较轻、学历较高的专业人士和白领人群当中,还包括大学生群体,我们应该针对这些群体采取相应的措施减轻他们的心身不适。  相似文献   
898.
Ordered nanostructured cobalt-doped nickel oxide films were prepared on a conducting glass substrate via the sol–gel dip-coating method. X-ray diffraction analysis shows the films to be amorphous. Field-emission scanning electron microscope images showed well-defined, ordered grains with pores in between them. Supercapacitor behaviour was studied using cyclic voltammetry. A maximum specific capacitance of 1982?F/g at a scan rate of 5?mV/s with 1?M KOH was obtained for 5?wt% of cobalt-doped nickel oxide films. AC impedance analysis showed that the solution resistance was R s?=?27?Ω and the charge transfer resistance R ct?=?20?Ω.  相似文献   
899.
The evolution of deformation texture in a Ni–60Co alloy with low stacking fault energy and a grain size in the nanometre range has been investigated. The analyses of texture and microstructure suggest different mechanisms of deformation in nanocrystalline as compared to microcrystalline Ni–60Co alloy. In nanocrystalline material, the mechanism responsible for texture formation has been identified as partial slip, whereas in microcrystalline material, a characteristic texture forms due to twinning and shear banding.  相似文献   
900.
When compatible and incompatible mappings of a location-relevant task are mixed, or a location-relevant task is mixed with a task for which stimulus location is irrelevant, the benefit of the compatible mapping is eliminated for physical locations and enhanced for location words. Two experiments examined the influence of presenting the location information for the mixed conditions in different stimulus modes (physical location or word). Experiment 1 showed that the effects of mixing location-relevant and location-irrelevant tasks on the spatial compatibility and Simon effects are reduced when the location information is presented in different modes for the two tasks. Experiment 2 showed, in contrast, that the mode distinction had little influence on the effects of mixed compatible and incompatible mappings for location-relevant tasks: The compatibility effect was eliminated for physical locations and enhanced for words, as when there is no mode distinction. Thus, when location is relevant for one task and colour for the other, the task-defined associations of locations to responses are mode specific, but when location is relevant for both tasks, the associations are mode independent.  相似文献   
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