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891.
A latent-variable study examined whether verbal and visuospatial working memory (WM) capacity measures reflect a primarily domain-general construct by testing 236 participants in 3 span tests each of verbal WM. visuospatial WM, verbal short-term memory (STM), and visuospatial STM. as well as in tests of verbal and spatial reasoning and general fluid intelligence (Gf). Confirmatory' factor analyses and structural equation models indicated that the WM tasks largely reflected a domain-general factor, whereas STM tasks, based on the same stimuli as the WM tasks, were much more domain specific. The WM construct was a strong predictor of Gf and a weaker predictor of domain-specific reasoning, and the reverse was true for the STM construct. The findings support a domain-general view of WM capacity, in which executive-attention processes drive the broad predictive utility of WM span measures, and domain-specific storage and rehearsal processes relate more strongly to domain-specific aspects of complex cognition.  相似文献   
892.
Practice effects in memory testing complicate the interpretation of score changes over repeated testings, particularly in clinical applications. Consequently, several alternative forms of the Auditory Verbal Learning Test (AVLT) have been developed. Studies of these typically indicate that the forms examined are equivalent. However, the implication that the forms in the literature are interchangeable must be tempered by several caveats. Few studies of equivalence have been undertaken; most are restricted to the comparison of single pairs of forms, and the pairings vary across studies. These limitations are exacerbated by the minimal overlapping across studies in variables reported, or in the analyses of equivalence undertaken. The data generated by these studies are nonetheless valuable, as significant practice effects result from serial use of the same form. The available data on alternative AVLT forms are summarized, and recommendations regarding form development and the determination of form equivalence are offered.  相似文献   
893.
A high percentage of Parkinson's disease (PD) patients show cognitive impairments in addition to the cardinal motor symptoms. These deficits primarily concern executive functions most probably linked to dysfunctions in prefrontal regions due to decreased dopaminergic transmission in fronto-striatal loops. To investigate possible associations between decision-making and executive functions in PD, we examined 20 non-demented PD patients and 20 healthy control subjects with a neuropsychological test battery and the Game of Dice Task. In this computerised decision-making task, the rules for gains and losses and the winning probabilities are obvious and stable. Thus, strategic components besides feedback processing might influence decision-making in this task. We found that PD patients were impaired in the Game of Dice task performance and that the frequency of disadvantageous choices correlated with both executive functions and feedback processing. We suggest that decision-making deficits of PD patients in explicit gambling situations might be associated with dysfunctions in two different fronto-striatal loops: the limbic-orbitofrontal-striatal loop, involved in feedback processing, and the dorsolateral prefrontal-striatal loop, involved in executive functions.  相似文献   
894.
The human voice was one of the more elusive acoustical phenomena to study in the 19th century and therefore a crucial test of Hermann von Helmholtz's new theory of sound. This article describes the origins of instruments used to study vowel sounds: synthesizers for production, resonators for detection, and manometric flames for visual display. Instrument maker Rudolph Koenig played a leading role in transforming Helmholtz's ideas into apparatus. In particular, he was the first to make the human voice visible for research and teaching. Koenig's work reveals the rich context of science, craft traditions, experiment, demonstration culture, and commerce in his Paris workshop.  相似文献   
895.
Mosher C  Rotolo T  Krupski DP  Stark KD 《Adolescence》2004,39(155):489-502
Despite the fact that inhalant use is a growing problem among youth in the United States, relatively little attention has been paid to the demographic and social factors related to its use. This study used data from a household survey of adolescents in Washington state, and found that race/ethnicity was a strong predictor of lifetime prevalence of inhalant use, with Native-American youth being particularly likely to use inhalants. Comparing the age at initiation of inhalant use to other legal and illegal substances, we found that cigarettes and inhalants showed the lowest age at initiation. We conducted logistic regressions on lifetime prevalence of inhalant use, and compared these models to other substances. In general, we found that attachment to parents. parents' drug use, and school attachment were strong predictors of lifetime use of marijuana, alcohol, and inhalants. However, while peer drug use was a strong predictor of marijuana and alcohol use, it was not a significant predictor of adolescents' use of inhalants. Our final set of analyses included inhalant use in regression models predicting other problem behaviors: these analyses demonstrated that inhalant use was a strong predictor of involvement in problem behavior.  相似文献   
896.
897.
At the bedside     
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898.
A startle stimulus has been shown to elicit a ballistic response in a reaction time (RT) task at very short latencies without involvement of the cerebral cortex (J. Valls-Sole, J. C. Rothwell, F. Gooulard, G. Cossu, & E. Munoz, 1999). The present authors examined the nature of the startle response. A simple RT task was used in which 8 participants performed arm extension movements to 3 target distances (20 degrees, 40 degrees, and 60 degrees ) in a blocked design. An unpredictable startling acoustic stimulus (124 dB) replaced the imperative stimulus in certain trials. The authors verified the presence of a startle response independent from the prepared response by observing electromyographic (EMG) activity in sternocleidomastoid and orbicularis oculi muscles. Findings indicated that when the participant was startled, the intended voluntary response was produced at significantly shorter response latencies. Furthermore, the kinematic variables of the observed response during startle trials for all 3 target distances were mostly unchanged. The EMG characteristics of the responses were not modified, indicating that the response produced was indeed the prepared and intended response.  相似文献   
899.
The authors examined a cross-sectional interrelationship of psychosocial domains as they relate to aggression in a group of African American and English-speaking Puerto Rican children living in New York City. The population included 80 biological children of African American and Puerto Rican young adults who had been participating in the authors' ongoing longitudinal study, and 77 mothers or mother substitutes (rearing mothers) of those children. The authors performed hierarchical multiple regression analysis. The results indicated that (a) the child's personality and maternal attributes were significantly related to the child's aggression, despite control on all of the other domains and (b) the ethnic identification and discrimination domain was no longer related to the child's aggression with control on the mother-child relationship domain or on the child's personality domain. The findings have implications for clinical practice and public policy.  相似文献   
900.
The authors argue that specific emotions can alter the persuasive impact of messages as a function of the emotional framing of persuasive appeals. Because specific emotions inflate expectancies for events possessing matching emotional overtones (D. DeSteno, R. E. Petty, D. T. Wegener, & D. D. Rucker, 2000), the authors predicted that attempts at persuasion would be more successful when messages were framed with emotional overtones matching the emotional state of the receiver and that these changes would be mediated by emotion-induced biases involving expectancies attached to arguments contained in the messages. Two studies manipulating discrete negative emotional states and message frames (i.e., sadness and anger) confirmed these predictions. The functioning of this emotion-matching bias in parallel with emotion-induced processing differences and the limitations of a valence-based approach to the study of attitude change are also considered.  相似文献   
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