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191.
Studies have shown that task sets could be configured endogenously (i.e., on the basis of memory) according to an explicit sequence or exogenously according to a task cue. In two experiments, we examined whether an implicitly learned sequence could facilitate task set configuration without participants’ intention. These experiments led to opposite conclusions regarding this question, but their methodology made it impossible to distinguish between the interpretations. We altered the task-switching paradigm by embedding a hidden task sequence, while randomizing all other aspects, including perceptual (i.e., task cues) and motor elements. We found that a sequence of tasks, proper, was learned implicitly and that the memory of that sequence endogenously facilitated task decision processes without the participants’ explicit knowledge.  相似文献   
192.
Rationale. Hypertension is considered a risk factor for the development of cognitive disorders, because of its negative effects on cerebral vasculature and blood flow. Genetically induced hypertension in rats has been associated with a range of cognitive impairments. Therefore, spontaneously hypertensive rats (SHR) can potentially be used as a model for cognitive deficits in human subjects. Consecutively, it can be determined whether certain food components can improve cognition in these rats. Objective. The present study aimed to determine whether SHR display specific deficits in attention, learning, and memory function. Additionally, effects of chronic uridine and choline administration were studied. Methods. 5-7 months old SHR were compared with normotensive Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats. (a) The operant delayed non-matching-to-position (DNMTP) test was used to study short-term memory function. (b) The five-choice serial reaction time (5-CSRT) task was used to assess selective visual attention processes. (c) Finally, the Morris water maze (MWM) acquisition was used as a measure for spatial learning and mnemonic capabilities. Results. (1) SHR exhibited significantly impaired performance in the 5-CSRT test in comparison with the two other rat strains. Both the SHR and WKY showed deficits in spatial learning when compared with the SD rats. (2) Uridine and choline supplementation normalized performance of SHR in the 5-CSRT test. (3) In addition, uridine and choline treatment improved MWM acquisition in both WKY and SHR rats. Conclusion. The present results show that the SHR have a deficiency in visual selective attention and spatial learning. Therefore, the SHR may provide an interesting model in the screening of substances with therapeutic potential for treatment of cognitive disorders. A combination of uridine and choline administration improved selective attention and spatial learning in SHR.  相似文献   
193.
Measures of icon designs rely heavily on surveys of the perceptions of population samples. Thus, measuring the extent to which changes in the structure of an icon will alter its perceived complexity can be costly and slow. An automated system capable of producing reliable estimates of perceived complexity could reduce development costs and time. Measures of icon complexity developed by Garcia, Badre, and Stasko (1994) and McDougall, Curry, and de Bruijn (1999) were correlated with six icon properties measured using Matlab (MathWorks, 2001) software, which uses image-processing techniques to measure icon properties. The six icon properties measured were icon foreground, the number of objects in an icon, the number of holes in those objects, and two calculations of icon edges and homogeneity in icon structure. The strongest correlates with human judgments of perceived icon complexity (McDougall et al., 1999) were structural variability (r s = .65) and edge information (r s = .64).  相似文献   
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195.
Counselling has taken on the trappings of a profession, via registration, accreditation, supervision and codes of ethics, but how far has it achieved the reality? What about content, outcomes, quality? Are we achieving more than amateurs? Is there a ‘high’ road and a low’ road to professionalisation? Which one shall we travel?  相似文献   
196.
The school placement of 122 aggressive, 150 withdrawn, 182 aggressive-withdrawn, and 299 control children was determined 3 years following their original selection. Children identified by peers as aggressive-withdrawn or aggressive were more likely to have failed a grade or to be in a special class than were withdrawn children or controls. Older aggressive-withdrawn subjects and controls, but not aggressive subjects or withdrawn subjects, had higher rates of school failure and special class placement. Fewer boys than girls were in a regular class at the expected grade level. The results underline the importance of childhood aggression as a predictor of later academic adjustment. Implications of these findings for the interpretation of measures of behavioral stability are discussed.The research reported here was supported by Quebec Ministry of Social Affairs Grant RS 281 to Jane Ledingham and Alex Schwartzman. The authors would like to thank the Commission des Ecoles Catholiques de Montréal for their continuing cooperation in this project, and Debbie Moskowitz and Alastair Younger for their constructive comments on an earlier draft.  相似文献   
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198.
The training and maintenance of imitative responding has become an important therapeutic process with language-handicapped children, as indicated by Garcia and DeHaven (American Journal of Mental Deficiency, 1974, 79 , 169–178). Typically a training “package” is used, that might entail the use of operant shaping, fading, reinforcement, and punishment techniques designed to increase correct imitation and decrease incorrect responding. Only recently have studies begun to concentrate on the components of these training “packages”. Steinman (Journal of Applied Behavior Analysis, 1970, 3 , 159–167) highlighted the roles played by less conspicuous but functionally important components of these packages. The present study attempted to provide a systematic extension of this work within an applied context. Using subjects who were responding at high levels during an imitation-maintenance procedure, experimenter facial orientation (experimenter's eyes and head oriented towards the subject's face and head), was systematically manipulated for experimentally determined “types” of imitative behavior. Differential responding within these parameters provided an evaluation of facial orientation as a functional component within this training package. Three retarded children participated in the study. Two types of topographically different imitative responses were defined for experimental purposes (“standing” and “sitting”). Each subject progressed through four conditions of the study, which called for the reinforcement of all imitative responses. But during preselected conditions, experimenter facial orientation was removed from the therapeutic package for one of the two topographical types of imitation. Results indicated that imitation of the two topographical types of models was dependent on the presence of experimenter facial orientation within the experimental procedure.  相似文献   
199.
Effects of an 18-minute videotape promoting nontraditional career choices of 986 eighth-grade and 11th-grade girls and boys from rural and urban schools were examined. Models were women and men in occupations traditionally held by the opposite sex. Posttreatment realistic, investigative, and social interests of the treatment group who viewed the videotape were compared with a control group that received a minimal intervention. There was not a main effect for the brief videotape treatment. Boys in the treatment group expressed significantly higher social interests at posttest than did control group boys. Findings indicate that brief interventions promoting nontraditional careers have limited impact.  相似文献   
200.
The comparatively lower prevalence of eating disorders among Asian and Afro-Caribbean than Caucasian women in the UK has often been attributed to cultural differences in pressures for slimness. However, there have been no attempts to evaluate cultural differences in ideals for female physique directly among women in the at risk age groups. In the present study, cultural influences on body image were evaluated by comparing the body size ideals, body image and dieting concerns in a sample of 274 young white and Asian British women. The results indicate that Asian women are less likely to describe themselves as too fat, were less dissatisfied with their body size, less likely to want to lose weight and less restrained. However, Asian women were slimmer than white women and, after controlling for the difference in body size, the effects were reduced. The hypothesis that any body satisfaction differences could be explained by differences in ideal body size between the two groups were not supported; Asian women favoured even slimmer ideal body sizes than white women. Alternative explanations in terms of cultural differences in evaluation of fatness are discussed.  相似文献   
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