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AX+, BX- discrimination learning in the fear-potentiated startle paradigm: possible relevance to inhibitory fear learning in extinction 下载免费PDF全文
The neural mechanisms of fear suppression most commonly are studied through the use of extinction, a behavioral procedure in which a feared stimulus (i.e., one previously paired with shock) is nonreinforced repeatedly, leading to a reduction or elimination of the fear response. Although extinction is perhaps the most convenient index of fear inhibition, a great deal of behavioral work suggests that postextinction training conditioned stimuli are both excitatory and inhibitory, making it difficult to determine whether a neural manipulation affects inhibition, excitation, or some combination thereof. For this reason we sought to develop a behavioral procedure that would render a stimulus primarily inhibitory while at the same time avoiding some of the issues raised by the traditional conditioned inhibition paradigm, namely second-order conditioning, external inhibition, and configural learning. Using the fear-potentiated startle paradigm, we adapted an AX+, BX- training procedure in which stimuli A and X were presented simultaneously and paired with shock, and stimuli B and X were presented simultaneously in the absence of shock. In testing, high levels of fear-potentiated startle were seen in the presence of A and AX and much lower levels were seen in the presence of B and AB, as would be predicted if stimulus B were a conditioned inhibitor. We believe this method is a viable alternative to the traditional conditioned inhibition training procedure and will be useful for studying the neural mechanisms of fear inhibition. 相似文献
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Although environmental enrichment improves spatial memory and alters synaptic plasticity in aged rodents, it is unclear whether all types of enrichment treatments yield similar benefits. The present study examined the effects in aged male mice of three types of enrichment on spatial memory in Morris water maze and radial arm maze tasks, and on levels of the presynaptic protein synaptophysin in several brain regions. Non-enriched young and aged males were compared with males exposed to one of the following treatments for 10 weeks: 5 min of daily handling, 3 h of daily basic enrichment, or 24 h of continuous complex enrichment. Young controls outperformed aged controls in both tasks. Neither daily handling nor daily enrichment affected spatial memory or synaptophysin levels. In contrast, continuous enrichment significantly reduced age-related spatial memory decline in both tasks, such that this group was statistically indistinguishable from young controls in most measures of performance. Continuously enriched mice were also significantly better than other aged mice in several spatial memory measures. Despite these improvements, synaptophysin levels in the continuous enrichment group were significantly lower than those of young and aged controls in the frontoparietal cortex, hippocampus, and striatum, suggesting a negative relationship between synaptophysin levels and spatial memory in aged males. These data demonstrate that different types of enrichment in aged male mice have disparate effects on spatial memory, and that the relationship between enrichment-induced changes in synaptophysin levels and spatial memory in aged males differs from that we have previously reported in aged female mice. 相似文献
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The objective of this study was to conduct an evidence-based review of treatments for depression in older adults in the primary care setting. A literature search was conducted using PsycINFO and Medline to identify relevant, English language studies published from January 1994 to April 2004 with samples aged 55 and older. Studies were required to be randomized controlled trials that compared psychosocial interventions conducted within the primary care setting with "usual care" conditions. Eight studies with older adult samples met inclusion criteria and were included in the review. Two treatment models were evident: Geriatric Evaluation Management (GEM) clinics and an approach labeled integrated health care models. Support was found for each model, with improvement in depressive symptoms and better outcomes than usual care; however, findings varied by depression severity, and interventions were difficult to compare. Further efforts to improve research and clinical care of depression in the primary care setting for older adults are needed. The authors recommend the use of interdisciplinary teams and more implementation of psychosocial treatments shown to be effective for older adults. 相似文献
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Using a nonconcurrent multiple baseline design, we evaluated the effects of extinction and stimulus control on nighttime sleep disturbances exhibited by 7 infants. Results showed that frequency and duration of night wakings decreased for all subjects, with corresponding improvements reflected through changes in responses to the sleep behavior scale. Observed improvements maintained at 3 and 24 months posttreatment. 相似文献
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Karyn Doba Jean-Louis Nandrino Annick Lesne Laurent Pezard 《New Ideas in Psychology》2008,26(2):295-308
Family theories of anorexia nervosa point out that patients’ autobiographic speech may reflect internalized family interactions. Our study characterizes the statistical distribution and temporal organization of the narrative components describing personal relationships in anorexic and control subjects. Semantic components related to personal interactions were encoded from life narratives of 14 adolescent girls with anorexia nervosa (restrictive type) and of 13 matched healthy adolescent girls. Speech analysis was performed using both statistical methods and non-linear time-series analysis. Static indices showed an over-representation of family relations and an under-representation of love relations in anorexic patients. Dynamical indices showed the independence between relational systems in anorexic patients. Dynamical analysis reveals that interactional patterns are internalized through the temporal organization of autobiographical speech. Moreover, these results support the existence of a specific temporal organization in anorexic adolescents’ life narratives which express the internalization of stationary family patterns and indicate relative inability to disengage from active previous relational patterns and to create new ones. 相似文献
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This research examines the long‐term ability of the consumers’ need for uniqueness measure to predict consumers’ valued possessions, shopping behaviors, and experiences. Consumers’ need for uniqueness reflects individual differences in counterconformity motivation (i.e., the pursuit of differentness relative to others) that is manifest in consumer responses. This research reports on 2 longitudinal assessments of the scale's predictive validity using data collected at 4 stages from a consumer mail‐survey sample. One year following initial responses to the trait measure, respondents participated in a second survey in which they photographed and rank ordered their valued possessions. In a third survey, the photographs served as cues to obtain responses to ratings of possession benefits and to questions regarding acquisition of the possession. Overall, the results support a number of hypotheses regarding the relation of consumers’ need for uniqueness to salient possession benefits, types of goods comprising consumers’ valued possessions, and shopping behaviors associated with acquiring valued possessions. Two years following initial responses to the trait measure, members of the consumer mail panel completed a fourth survey, indicating their participation in various uniqueness‐enhancing consumer activities. Results support the stability and predictive validity of the measure over the 2‐year period. Because the design of possessions and endorsed uniqueness‐enhancing activities considered in the consumer mail panel studies varied across individuals, an additional study was conducted that demonstrated the scale's ability to predict individuals’ counterconformity responses to the same choice situation. 相似文献
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