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991.
Three studies are presented testing a model of the cognitive performance deficits shown in depression. The model proposes that such deficits occur as an interaction of expectancy and focus of attention variables, that is, in the presence of both low expectancy of success and high self-focus. Study 1 was a pilot study which documented that depressed undergraduates evidence poorer anagram performance, greater self-focus, and lower pretask expectancies than do nondepressed subjects. Study 2 showed that nondepressed undergraduates evidence performance deficits only when both expectancy is lowered and self-focus is increased. Study 3 suggested that depressed undergraduates' performance deficits are overcome either by lowering self-focus or by raising expectancy. Discussed are discrepancies between self-report and performance data, the relevance of these studies to the test anxiety literature, the need to integrate literature concerning the effects of depression, anxiety, and self-esteem on performance, and how the interactive roles of positive expectancy and focus of attention may be related to effective coping in a variety of situations.  相似文献   
992.
Historically, women and minority group members have been underrepresented in the professions and in better paying, high-status jobs. Even when they have been admitted to such positions, these underrepresented persons often have been the only member of their social category: a token. Previous field and laboratory research has shown that "tokens" attract disproportionate attention and are either evaluated unfairly or evaluated on the basis of their normal reactions to differential treatment by majority group members. We tested the possibilities of whether tokens might suffer more cognitive deficits than would nontokens, and whether they do so even when they are treated no differently. College students were led to believe that they were sharing their views on everyday topics with three other students (actually videotaped confederates), who were either all of the student's own sex or all of the opposite sex. In a later memory test, token participants remembered fewer of the opinions that they and the three other students had expressed than did nontokens. Observers, in contrast, remembered more of what token subjects said than what the three other students said. Theoretical and public policy implications are discussed.  相似文献   
993.
Models are sometimes developed on the premise that there are no differences between two or more conditions regardless of experimental manipulation. This article argues that unless a very sensitive experiment (or series of experiments) was conducted, such conclusions are often premature. Design and statistical factors such as alpha level, variability, sample size, and treatment effect are all determinants of the sensitivity of the experiment. It is sometimes the case that an experiment produces differences between means and yet the null hypothesis is not rejected because of high variability within experimental conditions or because too few subjects were used. Unless the probability of detecting a difference between groups is known, it would seem unwise to conclude that no difference exists. Judgment on the model should be suspended. Examples are taken from the mass-spring and pulse-step models fro voluntary movement control to illustrate the problem.  相似文献   
994.
The growth of stability: postural control from a development perspective   总被引:5,自引:0,他引:5  
This study compared central nervous system organizational processes underlying balance in children of three age groups: 15-31 months, 4-6 years, and 7-10 years, using a movable platform capable of antero-posterior (A-P) displacements or dorsi-plantar flexing rotations of the ankle joint. A servo system capable of linking platform rotations to A-P sway angle allowed disruption of ankle joint inputs, to test the effects of incongruent sensory inputs on response patterns. Surface electromyography was used to quantify latency and response patterns. Surface electromyography was used to quantify latency and amplitude of the gastrocnemius, hamstrings, tibialis anterior, and quadriceps muscle responses. Cinematography provided biomechanical analysis of the sway motion. Results demonstrated that while directionally specific response synergies are present in children under the age of six, structured organization of the synergies is not yet fully developed since variability in timing and amplitude relationships between proximal and distal muscles is high. Transition from immature to mature response patterns was not linear but stage-like with greatest variability in the 4- to 6- year-old children. Results from balance tests under altered sensory conditions (eyes closed and/or ankle joint inputs altered) suggested that: (a) with development a shift in controlling inputs to posture from visual dependence to more adult-like dependence on a combination of ankle joint and visual inputs occurred in the 4- to 6-year-old, and reached adult form in the 7- to 10-year-old age group. It is proposed that the age 4-6 is a transition period in the development of posture control. At this time the nervous system (a) uses visual-vestibular inputs to fine tune ankle-joint proprioception in preparation for its increased importance in posture control and (b) fine tunes the structural organization of the postural synergies themselves.  相似文献   
995.
The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.  相似文献   
996.
We show that self-ratings by 141 undergraduates on 17 items form a circumplex that closely agrees with Conte and Plutchik's (1981) circumplex of personality traits. The order of items on a circumplex, generated by self-ratings following a here-and-now instruction set, scarcely differs from that of a circumplex representing the same ratings averaged over a 2-week period. The configuration becomes more elliptical as one moves from the state-like measures (here-and-now ratings) to pure trait measures (averages), but measurement bias is shown to be the most probable cause of the distortion. Allowing for the limitations of small samples of items and raters, the findings show that the circumplex model represents a valid theoretical construct and does not arise from measurement error or from an illusory implicit personality theory.  相似文献   
997.
Conditioned placebo responses   总被引:4,自引:0,他引:4  
Following earlier animal research, we attempt to condition placebo effects in human subjects. Four groups of 8 voluntary subjects were told that the experimenters would test a powerful new analgesic cream over three sessions by assessing its ability to reduce experimentally induced pain. The analgesic cream was, in fact, a placebo. In the first session all subjects were tested with and without the cream to assess their placebo response. In the second session, to condition two groups (with differing stimulation levels) to experience pain relief in response to the placebo, we repeatedly paired a reduction in nocioceptive stimulation with placebo administration. (Subjects were unaware that stimulation levels were manipulated). To condition the other two groups (with different stimulation levels) to experience an exacerbation of the pain, we paired an increase in nocioceptive stimulation with placebo administration. In the third session, all subjects were again tested for placebo response. Results suggested that placebo responses are conditionable in the laboratory in both a positive and negative direction. The clinical implications of a learning theory of placebo behavior are discussed.  相似文献   
998.
According to the physiological animal model proposed by Gorenstein and Newman (1980; see also Newman, Gorenstein, & Kelsey, 1983), psychopaths and extraverts may be characterized by a common psychological diathesis related to behavioral inhibition (see also Fowles, 1980; Gray, 1982). One aspect of this diathesis involves deficient passive avoidance learning, which has been central to explanations of "unsocialized" (e.g., Trasler, 1978) and antisocial behavior (e.g., Hare, 1970). Results from three experiments supported our prediction that psychopaths and extraverts would exhibit deficient passive avoidance relative to nonpsychopaths and introverts, respectively. In addition, the passive avoidance deficit was particularly evident in tasks that required subjects to inhibit a rewarded response in order to avoid punishment. The latter finding may be important for explaining the inconsistent results regarding passive avoidance learning in psychopaths (e.g., Chesno & Kilmann, 1975; Schmauk, 1970). Discussion of the results focuses on the importance of reward in mediating the passive avoidance deficit of "disinhibited" individuals and on the existence of an indirect relationship between psychopathy and extraversion: one that is consistent with the observed experimental parallels as well as with the more ambiguous evidence regarding a direct correlation between measures of the two syndromes.  相似文献   
999.
1000.
Checklists of children's nighttime fears and nighttime coping responses, completed by 178 8- to 13-year-old children and one of their parents, were factor analyzed. The resulting factors from each checklist were comparable for children and parents. The nighttime fear categories consisted of content around security either for one's personal life, loss, or safety or for others' safety and continued presence; imaginal-numinous concerns; and characteristics inherent in a nighttime situation. The coping categories consisted of responses related to internal self-control, social support, support from inanimate objects, prayer, and avoidance or escape either by controlling the inanimate environment or by controlling others.  相似文献   
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