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951.
Sharon H. Thompson Sara J. Corwin Thomas J. Rogan Roger G. Sargent 《Journal of child and family studies》1999,8(1):91-108
African American and White mother/adolescent pairs were examined for familial associations in body size and weight concerns. Mothers' and adolescents' estimates of adolescents' body mass index (BMI) were significantly correlated. Compared to boys, girls had greater body dissatisfaction, higher weight concerns, and perceived higher family/friend weight concerns. By race, White adolescents had more body dissatisfaction and greater concern about weight than African American adolescents. Four items explained 70.4% of the variance in adolescents' weight concern scores: adolescents' weight management practices, mothers' reports of adolescents' saying they were too fat, adolescents' perceptions of family/friends' weight concerns, and adolescents' body dissatisfaction. Our study suggests White girls are more concerned about their weight and perceive greater weight and dieting concerns among family/friends than African American girls. 相似文献
952.
Benoît G. Bardy William H. Warren Bruce A. Kay 《Attention, perception & psychophysics》1999,61(7):1356-1368
Three hypotheses have been proposed for the roles of central and peripheral vision in the perception and control of self-motion: (1) peripheral dominance, (2) retinal invariance, and (3) differential sensitivity to radial flow. We investigated postural responses to optic flow patterns presented at different retinal eccentricities during walking in two experiments. Oscillating displays of radial flow (0° driver direction), lamellar flow (90°), and intermediate flow (30°, 45°) patterns were presented at retinal eccentricities of 0°, 30°, 45°, 60°, or 90° to participants walking on a treadmill, while compensatory body sway was measured. In general, postural responses were directionally specific, of comparable amplitude, and strongly coupled to the display for all flow patterns at all retinal eccentricities. One intermediate flow pattern (45°) yielded a bias in sway direction that was consistent with triangulation errors in locating the focus of expansion from visible flow vectors. The results demonstrate functionally specific postural responses in both central and peripheral vision, contrary to the peripheral dominance and differential sensitivity hypotheses, but consistent with retinal invariance. This finding emphasizes the importance of optic flow structure for postural control regardless of the retinal locus of stimulation. 相似文献
953.
Elizabeth S. Olds William B. Cowan Pierre Jolicoeur 《Attention, perception & psychophysics》1999,61(6):1038-1045
Visual attention can be goal driven, stimulus driven, or a combination of the two. Here we report evidence for an unexpectedly stimulus-driven component of visual search for a target defined by color. Observers demonstrated a surprisingly cost-free ability to incorporate multiple classifiers in search for a target of one color from among distractors of other colors. A target color was presented among distractors that could change from trial to trial (intermixed presentation) or that remained constant across all trials in a block (blocked presentation). For blocked presentation, a single search classifier (a mechanism that segregates the target from distractors in color space) could be adopted, whereas for intermixed presentation different classifiers had to be used when the distractor colors changed. The benefit of blocked presentation was very small, suggesting that the appropriate classifier was determined very quickly in trials for which the classifier changed. The results suggest that the stimulus-driven activation of an appropriate stimulus classifier can be very efficient. 相似文献
954.
A mirror effect was found for a stimulus manipulation introduced at test. When subjects studied a set of normal faces and then were tested with new and old faces that were normal or wearing sunglasses, the hit rate was higher and the false alarm rate was lower for normal faces. Hit rate differences were reflected in remember and sure recognition responses, whereas differences in false alarm rates were largely seen in know and unsure judgments. In contrast, when subjects studied faces wearing sunglasses, the hit rate was greater for test faces with sunglasses than for normal faces, but there was no difference in false alarm rates. These findings are problematic for single-factor theories of the mirror effect, but can be accommodated within a two-factor account. 相似文献
955.
Memory for previously learned figural sequences and item-to-item covariations within figural sequences was examined under explicit and implicit instructional conditions in three age groups: young adults (17-23 years); middle-aged adults (35-45 years); and older adults (55-65 years). In Phase 1 of the experiment, the acquisition phase, half the subjects in each age group learned sequences of three to eight items in which the item-to-item changes conformed to an artificial grammar, and the other half of the subjects in each age group learned strings in which the item-to-item changes were nongrammatical. In Phase 2, the implicit/explicit test phase, subjects made forced-choice judgments about parts of the strings that they learned in Phase 1, under either explicit or implicit instructions. Analyses of Phase 2 data revealed that subjects in both instructional conditions used item-to-item covariations in making decisions about grammatical strings. However, use of previously learned covariations as well as the number of correct judgments about previously learned strings was greater in the explicit condition than in the implicit condition. An age-related deficit was found for explicit recognition of grammar-following sequences. 相似文献
956.
Neuropsychological function and apolipoprotein E genotype in the preclinical detection of Alzheimer's disease. 总被引:12,自引:0,他引:12
Nondemented older adults genotyped for the Apolipoprotein E (ApoE) epsilon4 allele (n = 43) were neuropsychologically compared to participants without a copy of the epsilon4 allele (n = 90). At baseline, the groups did not differ on age, education, gender, or global cognitive status. ApoE-epsilon4 participants demonstrated significantly poorer mean performances on delayed recall, but no significant group differences emerged on attention, language, constructional skills, psychomotor speed, or executive function. Significantly more ApoE-epsilon4 participants developed probable or questionable Alzheimer's disease (AD) compared with non-epsilon4 participants, suggesting that the group differences resulted from a preponderance of preclinical AD cases within the epsilon4 group and not from a direct influence of ApoE genotype on cognition. Cox proportional hazards analysis, adjusting for age, years of education, and global cognitive status, revealed that ApoE-epsilon4 allele status and measures of recall performance were significant and independent predictors of conversion to AD. Results support the importance of specific episodic memory changes and possession of the ApoE-epsilon4 allele in the preclinical detection of AD. 相似文献
957.
Jody L. Swartz-Kulstad William E. Martin 《Journal of counseling and development : JCD》1999,77(3):281-293
The growing diversity of the American population requires of counselors an increased understanding of inter- and intracultural factors. All clients have culture, and contextualized cultural variables can and do affect an individual's ability to adapt to his or her environment. Adaptation difficulties typically produce concerns that further affect the individual's functioning. Counselors need to incorporate contextualized cultural factors into their conceptualization of the individual's concerns and the treatment process. Use of the Cultural and Contextual Guide Process to facilitate inclusion of contextualized culture in the counseling process is discussed and a case study is used to exemplify the process. 相似文献
958.
Emyr Vaughan Thomas 《Ratio》1999,12(2):195-209
Wittgenstein is widely recognised as a philosopher with a markedly ethical character to his thought. This paper seeks to highlight the dimension of selflessness and renunciation in this ethical character. It also seeks to show that there are distinct differences in Wittgenstein's implicit conception of what an ethical selflessness amounts to in the early and the later periods. The concept of absolute safety enables us to appreciate the connections between the early Wittgenstein and a particular type of nineteenth-century obsession with a selflessness that combines with a self-sufficient capacity to stand aloof from anxiety in the face of the human condition involving meaninglessness and death. In the early Wittgenstein that aloofness came close to a solipsistic and, in some ways, self-affirming apartness from everything other than the self. In contrast, the ethical spirit that permeates Wittgenstein's later thought is imbued with a sense of the immersion of the self ultimately and absolutely 'in the world'. The sense in which this latter phrase is used is defined further in the paper. 相似文献
959.
We explored shift costs for a dimensionally organized set of tasks. Task dimensions were type of judgement (numerical vs.
spatial) and judgement-to-response mapping (compatible vs. incompatible). Shift costs were determined as the difference in
RTs between switch trials and repetitions in a situation in which the kind of task was unpredictable. Shift costs were greatest
when the type of judgement was changed. A change in the mapping increased shift costs when the type of judgement remained
unchanged, but reduced shift costs when the type of judgement was changed as well. Also, response alternations produced costs
when both the type of judgement and SR mapping were unchanged, but reduced shift costs otherwise. In addition to the relation
between successive tasks, shift costs were modulated by the specifics of the elementary tasks. The major characteristics of
the pattern of shift costs could be accounted for by the hypothesis of a dimensionally organized task space in which hierarchically
organized, relative switching operations are performed that affect the highest-level task dimension at which a change is required,
and all lower-level dimensions in a first step. In a second step, lower-level dimensions are switched back when no change
is required, and then the selected control structure is implemented.
Received: 11 December 1997 / Accepted: 6 July 1998 相似文献
960.
Christopher D. Ratcliff Michael Czuchry Nikki C. Scarberry Jennifer C. Thomas Donald F. Dansereau Charles G. Lord 《Journal of applied social psychology》1999,29(5):994-1009
An important application of psychological principles involves increasing intentions to engage in activities that, although admittedly beneficial, are often not initially appealing (e.g., studying, quitting smoking, dieting). The present study tests the utility of directed thinking as a tool for eliciting intentions to engage in such activities. Undergraduate students were directed to think either about the reasons why people should find studying enjoyable or about the actions that people might take to make studying enjoyable. Regardless of whether they thought as individuals or in cooperating dyads, students who thought about actions later reported greater intentions to spend time studying than did students who thought about reasons. The results have both theoretical and practical significance. 相似文献