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841.
The focus of this work was on the relation between grammatical gender and categorization. In one set of studies, monolingual English-, Spanish-, French-, and German-speaking children and adults assigned male and female voices to inanimate objects. Results from Spanish and French speakers indicated effects of grammatical gender on classification; results from German speakers did not. A connectionist model simulated the contradicting findings. The connectionist networks were also used to investigate which aspect of grammatical gender was responsible for the different pattern of findings. The predictions from the connectionist simulations were supported by the results from an artificial language-learning task. The results from this work demonstrate how connectionist networks can be used to identify the differences between languages that affect categorization.  相似文献   
842.
Two studies investigated the mediating effects of liking and attributions of motives on the relationship between a ratee's reputation and helpful behaviors and raters' reward decisions. During managerial simulations, raters evaluated individuals after watching videotapes in which the individual's reputation and helpful behaviors were manipulated. Results indicated an interaction effect between reputation and helpful behaviors such that a helpful person with a good reputation received more rewards than did a helpful person with a bad reputation. In contrast, an unhelpful person with a good reputation did not receive better rewards than an unhelpful person with a bad reputation. Moreover, raters' liking of ratees and the motives raters attributed to ratees' helpful behaviors mediated the relationship between the manipulations and raters' reward decisions.  相似文献   
843.
The expertise paradigm was used in two studies to examine decision-making by rugby referees. Videoclips were used to assess infraction detection and knowledge base, or sources of information used. In Study 1, referees of high and low experience were compared, and in Study 2 referees and players were compared. Analysis by signal detection used a framework to classify types of information. Study 1 yielded no differences in detection of infractions as a function of experience, however, referees of high experience used significantly more sources of information than the group with low experience across all categories of information. In Study 2, there were no significant differences between referees and players, with the exception that referees displayed greater use of episodic memory information in decision-making.  相似文献   
844.
Although some laboratories have reported that a single session of stress is able to induce a long-lasting sensitisation of the hypothalamic-pituitary-adrenal (HPA) response to further exposures to stress, we have found that a single exposure to severe emotional (immobilisation, restraint or shock) or systemic (endotoxin) stressors reduces the responsiveness of the HPA to the same, but not to a novel (heterotypic), stressor, in which case a slight sensitisation was observed. Long-term desensitisation has been found to reduce not only secretion of peripheral HPA hormones (ACTH and corticosterone), but also to reduce responses of central components of the HPA axis (c-fos and CRF gene expression at the level of the paraventricular nucleus of the hypothalamus, PVN). In addition, desensitisation also applies to the impact of the stressor on food intake and, probably, to stress-induced hyperglycaemia. The development of long-term desensitisation of the HPA axis does not appear to be a universal consequence of exposure to severe stressors as it was not observed in response to insulin-induced hypoglycaemia. Whether or not the development of long-term effects of stress depend on the specific pathways activated by particular stressors remains to be tested. The observed desensitisation of the HPA axis in response to the homotypic stressor shows two special features which makes it difficult to be interpreted in terms of an habituation-like process: (a) the effect increased with time (days to weeks) elapsed between the first and second exposure to the stressor, suggesting a progressive maturational process; and (b) the stronger the stressor the greater the long-term desensitisation. Therefore, it is possible that desensitisation of the HPA axis is the sum of two different phenomena: long-term effects and habituation-like processes. The contribution of the former may be more relevant with severe stressors and longer inter-stress intervals, and that of the latter with mild stressors and repeated exposures. Long-term stress-induced changes may not take place at the level of the PVN itself, but in brain nuclei showing synaptic plasticity and putatively involved in the control of the HPA axis and other physiological responses. As for the precise areas involved, these remain to be characterized.  相似文献   
845.
Biomedical measures are critical in the initial patient-screening and -selection phases of a clinical trial in autism and related disorders. These measures can also play an important role in the assessment and characterization of response and can provide an opportunity to study underlying etiologic and pathophysiologic processes. Thus, biomedical measures, including clinical laboratory analyses, metabolic screening, and chromosomal analysis, are used to screen for potential safety-related problems, to decrease biological and genetic heterogeneity, and to define subgroups. Neurobiological measures can be examined as possible predictors, modifiers or surrogates of therapeutic response, and adverse effects. Neurobiological research measures can also be used to study mechanisms and extent of drug action and to perform baseline and longitudinal investigations of possible pathophysiologic alterations. The potential utility and desirability of specific measures are considered and the general approach to choosing measures for incorporation is discussed.  相似文献   
846.
We analyze the properties of a dynamic color-spreading display created by adding narrow colored flanks to rigidly moving black lines where these lines fall in the interior of a stationary virtual disk. This recently introduced display (Wollschl?ger et al, 2001 Perception 30 1423-1426) induces the perception of a colored transparent disk bounded by strong illusory contours. It provides a link between the classical neon-color-spreading effect and edge-induced color spreading as discussed by Pinna et al (2001 Vision Research 41 2669-2676). We performed three experiments to quantitatively study (i) the enhancing influence of apparent motion; (ii) the degrading effect of small spatial discontinuities (gaps) between lines and flanks; and (iii) the spatial extent of the color spreading. We interpret the results as due to varying degrees of objecthood of the dynamically specified disk: increased objecthood leads to increased surface visibility in both contour and color.  相似文献   
847.
Working memory is hypothesized to comprise a collection of distinct components or processes, each of which may have a unique neural substrate. Recent neuroimaging studies have isolated a region of the left inferior frontal gyrus that appears to be related specifically to one such component: resolving interference from previous items in working memory. In the present study, we examined working memory in patients with unilateral frontal lobe lesions by using a modified version of an item recognition task in which interference from previous trials was manipulated. In particular, we focused on patient R.C., whose lesion uniquely impinged on the region identified in the neuroimaging studies of interference effects. We measured baseline working memory performance and interference effects in R.C. and other frontal patients and in age-matched control subjects and young control subjects. Comparisons of each of these groups supported the following conclusions. Normal aging is associated with changes to both working memory and interference effects. Patients with frontal damage exhibited further declines in working memory but normal interference effects, with the exception of R.C., who exhibited a pronounced interference effect on both response time and accuracy. We propose that the left inferior frontal gyrus subserves a general, nonmnemonic function of selecting relevant information in the face of competing alternatives and that this function may be required by some working memory tasks.  相似文献   
848.
Predictors of Condom Use in Mexican Migrant Laborers   总被引:5,自引:0,他引:5  
The purpose of this study was to explore predictors of condom use with occasional sex partners and regular sex partners, as well as carrying condoms in a new high-risk group for HIV infection, Mexican migrant laborers. This study extends previous findings by (1) exploring additional predictors not previously examined, (2) utilizing a large sample of male and female Mexican migrant laborers, (3) carefully controlling for the effects of various demographic and lifestyle variables related to condom use, and (4) assessing the interactive effects of gender on predictors of condom use. Snowball sampling was used to survey 501 adult Mexican migrant laborers. Results revealed that condom use with occasional sex partners was predicted by carrying condoms and condom self-efficacy and that women were more likely to use condoms with occasional partners when both men and women knew someone with HIV/AIDS. Condom use with regular sex partners was predicted by procondom social norms, less negative attitudes toward condoms, not knowing someone with HIV/AIDS, and condom self-efficacy. Carrying condoms was predicted by procondom social norms, less negative attitudes toward condoms, condom self-efficacy, worry about contracting HIV/AIDS, and women were more likely than men to carry condoms when both men and women were married. Understanding these findings, future research directions, and implications for condom promotion strategies with Mexican migrant laborers are discussed.  相似文献   
849.
The impact of grades on daily self-esteem, affect, and identification with major was examined in a sample of 122 male and female students majoring in engineering and psychology. Self-esteem, affect, and identification with major increased on days students received good grades and decreased on days they received poor grades; basing self-esteem on academic competence moderated the effect of bad grades. Bad grades led to greater drops in self-esteem but not more disidentification with the major for women in engineering. Instability of self-esteem predicted increases in depressive symptoms for students initially more depressed.  相似文献   
850.
Critical requirements for the hypothesis that executive functioning is a potential mediator of age-related effects on cognitive functioning are that variables assumed to reflect executive functioning represent a distinct construct and that age-related effects on other types of cognitive functioning are reduced when measures of executive functioning are statistically controlled. These issues were investigated in a study involving 261 adults between 18 and 84 years of age. Although age-related effects on various cognitive abilities were substantially reduced after statistical control of the variance in measures hypothesized to represent executive functioning, there was only weak evidence for the existence of distinct constructs corresponding to executive functioning or to aspects of executive control concerned with inhibition, updating, or time sharing.  相似文献   
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