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21.
Rats were injected with scopolamine before every daily session of water reinforcement on a fixed-interval (FI) schedule. Initially the drug decreased the rate of responding. Control injections of scopolamine following each session did not. Over 119 sessions, the typical FI performance developed more slowly in the animals drugged before the sessions. Their rates of responding increased from session to session, to a level slightly greater than that of the animals drugged after the sessions. Their rates did not increase. The effects of injections before the session were not duplicated by increasing the deprivation of animals drugged after the session.  相似文献   
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Abstract— The relative predictive accuracy of humans and statistical models has long been the subject of controversy even though models have demonstrated superior performance in many studies. We propose that relative performance depends on the amount of contextual information available and whether it is distributed symmetrically to humans and models. Given their different strengths, human and statistical predictions can be profitably combined to improve prediction.  相似文献   
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Predictive testing for Huntington disease is presently offered in a select few medical genetics centers in the United States. This is in part due to the labor intensive counseling and psychological testing suggested by the research protocols. We discuss some specific suggestions for establishing programs for Huntington disease predictive testing within pre-existing medical genetics clinics to encourage more centers to offer presymptomatic testing. This will allow more at risk individuals the opportunity to consider predictive testing and cut down the expenses of traveling to the few predictive testing centers that currently exist. The counseling principals will remain similar to those discussed here, even following the identification of the Huntington disease mutation.  相似文献   
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Functional neuroimaging has been used to investigate neural substrates of mnemonic processes, and cerebral blood flow (CBF) measures have been sensitive to activation with memory tasks. Studies of memory with two-dimensional133Xenon clearance techniques found that word and face recognition tasks produced contralateral CBF changes in mid-temporal cortical regions. This study replicated the activation paradigm, expanding to the three-dimensional resolution of positron emission tomography (PET). Word and face recognition, and a control baseline task were administered to 19 healthy right-handed volunteers (11 men, 8 women) during successive 10 min PET15O-water measures of CBF. Quantitative CBF rates were calculated with the arterial input function and the equilibrium model. Redistributions of blood flow were compared across tasks using both absolute and relative (region/whole brain) CBF.Replicating the133Xenon clearance findings, CBF was “appropriately” lateralized during task performance (left–right for words > left–right for faces) in the mid-temporal region. Contrary to predictions, the recognition tasks did not activate expected mesolimbic or prefrontal areas. The task-induced CBF changes also correlated with performance. Bilateral CBF in mid-temporal and parahippocampal gyrus regions of interest correlated with the ability to correctly identify word targets (sensitivity). Left-lateralized CBF in the amygdala and hippocampus correlated with better word sensitivity as well as specificity (ability to correctly reject foils). Complementally, right-lateralized CBF in the parahippocampal gyrus correlated with better face specificity performance. In addition, left-lateralized CBF in the amygdala and right-lateralized CBF in the parahippocampal gyrus and hippocampus correlated with “mental effort” indices (task performance relative to basal ability) for word and face memory tasks, respectively. Thus, whereas this recognition task showed the expected lateralized increase in the mid-temporal region and not in frontal and limbic areas, lateralized activation in some of these areas was associated with better performance. Exploratory analyses on other regions showed lateralized changes in one additional temporal region, the occipital-temporal, and several limbic regions.  相似文献   
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A translation is given of Hirsch's pioneering paper of 1862 on chronoscopic experiments On the speed of different senses and nerve transmission. Hirsch was the first (1) to use Hipp's chronoscope in scientific literature, (2) to study reaction time in connection to psychological interest, and (3) to study velocity of conduction in humans with appropriate techniques. Using Hipp apparatus, Hirsch showed differences in time for manual response (1) to auditory, visual, and tactile stimulation; (2) between observers; (3) in Hirsch's own results when fresh and when fatigued; (4) according to the locus of tactile stimulation and the hand used for response; and (5) according to whether the stimulus was expected or unexpected. Moreover, observations made on one of his colleagues relate the conduction speed in nerves, from which he concludes that the differences in reaction time were due to the varying lengths of nerves. The speed of transmission in sensory nerves was evaluated by Hirsch at about 34 m/s. This work constitutes a prelude of Donders' research on the speed of mental processes.  相似文献   
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Top-of-the-head worries were elicited from young people, grades 4 to 8, both before and after they completed quantitative risk assessments of specific health and environmental problems. Results revealed that many students carry a substantial worry burden that includes not only personal matters such as grades and social relations, but also concerns about death and about global issues such as homelessness and environmental degradation. The gender and grade differences that emerged were consistent with a developmental extension from self to societal perspectives. Differences in worry profiles from before to after the risk assessment interviews revealed some impact of recent exposure, as illustrated by a pre—post increase from 7% to 30% in students spontaneously expressing AIDS-related concerns. Implications of the breadth and severity of young people's concerns are discussed, as are the ambiguities inherent in standard assessment approaches.This research was supported by grants from the National Institute of Child Health and Human Development (HD27035) and the University of California Universitywide AIDS Research Program (R901040). We very much appreciate the cooperation of Sally Snyder and the Irvine Unified School District, Amy Watson and the Corinne A. Seeds University Elementary School, Trina Panaqua and the Bruin Kids of UCLA, and the Fernald Child Study Center. Special thanks are due to the 4th- through 8th-grade student participants. We are also grateful to Ellen Dellis, Virginia Elderkin-Thompson, Judy Hollingshead, Alison Holman, Judy Koch-Jones, and Kim Witte for their help with the interviews and to Tammy Merlo, Shealen Nash, and Beth Twambley for competent coding assistance. Finally, we thank the anonymous editorial reviewers for constructive comments on the nature of fear and worry.  相似文献   
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The recent dramatic changes in the political and economic structures of Eastern Europe have focused interest on the position of women in Russia, where a greater openness in discussing inequalities has been accompanied by a more regressive harkening back to traditional gender roles. The study reported in this paper examines gender and occupational differences in general attitude toward the family, disclosure to family members, and child-rearing values. Three hundred sixty-eight students, 179 manual workers, and 160 entrepreneurs completed a structured measure of family orientation and replied to open-ended questions on family taboos and child-rearing practices, while a subsample (N = 475) completed a family disclosure inventory. Multivariate analyses of variance analyses revealed women to be more family oriented than men, while gender and occupation interacted in producing family disclosure rates. HILOGLINEAR analyses found that the topics suitable for family discussion, as well as the child-rearing values promoted by our respondents, were also best predicted by considering the interaction between both gender and occupation. The implications of these findings for the future shape of Russian family relations is discussed.  相似文献   
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