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Vidal-Gonzalez I Vidal-Gonzalez B Rauch SL Quirk GJ 《Learning & memory (Cold Spring Harbor, N.Y.)》2006,13(6):728-733
Recent studies using lesion, infusion, and unit-recording techniques suggest that the infralimbic (IL) subregion of medial prefrontal cortex (mPFC) is necessary for the inhibition of conditioned fear following extinction. Brief microstimulation of IL paired with conditioned tones, designed to mimic neuronal tone responses, reduces the expression of conditioned fear to the tone. In the present study we used microstimulation to investigate the role of additional mPFC subregions: the prelimbic (PL), dorsal anterior cingulate (ACd), and medial precentral (PrCm) cortices in the expression and extinction of conditioned fear. These are tone-responsive areas that have been implicated in both acquisition and extinction of conditioned fear. In contrast to IL, microstimulation of PL increased the expression of conditioned fear and prevented extinction. Microstimulation of ACd and PrCm had no effect. Under low-footshock conditions (to avoid ceiling levels of freezing), microstimulation of PL and IL had opposite effects, respectively increasing and decreasing freezing to the conditioned tone. We suggest that PL excites amygdala output and IL inhibits amygdala output, providing a mechanism for bidirectional modulation of fear expression. 相似文献
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As compared with conventional vaccine production systems, plant-made vaccines (PMVs) are said to enjoy a range of advantages including cost of production and ease of storage for distribution in developing countries. In this article, we introduce the science of PMV production, and address ethical issues associated with development and clinical testing of PMVs within three interrelated domains: PMVs as transgenic plants; PMVs as clinical research materials; and PMVs as agents of global health. We present three conclusions: first, while many of the ethical issues raised by PMVs are familiar, PMVs add a new dimension to old issues, and raise some novel issues for ethicists and policy-makers; secondly, it is premature to promise broad applicability of PMVs across the developing world without having demonstrated their feasibility; thirdly, in particular, proponents of PMVs as a solution to global health problems must, as a condition of the ethical conduct of their research, define the commercial feasibility of PMVs for distribution in the developing world. 相似文献
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Sinnett S Costa A Soto-Faraco S 《Quarterly journal of experimental psychology (2006)》2006,59(8):1425-1442
People often fail to consciously perceive visual events that are outside the focus of attention, a phenomenon referred to as inattentional blindness or IB (i.e., Mack & Rock, 1998). Here, we investigated IB for words within and across sensory modalities (visually and auditorily) in order to assess whether dividing attention across different senses has the same consequences as dividing attention within an individual sensory modality. Participants were asked to monitor a rapid stream of pictures or sounds presented concurrently with task-irrelevant words (spoken or written). A word recognition test was used to measure the processing for unattended words compared to word recognition levels after explicitly monitoring the word stream. We were able to produce high levels of IB for visually and auditorily presented words under unimodal conditions (Experiment 1) as well as under crossmodal conditions (Experiment 2). A further manipulation revealed, however, that IB is less prevalent when attention is divided across modalities than within the same modality (Experiment 3). These findings are explained in terms of the attentional load hypothesis and suggest that, contrary to some claims, attention resources are to a certain extent shared across sensory modalities. 相似文献
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We asked whether the ability to keep in working memory the binding between a visual object and its spatial location changes with development across the life span more than memory for item information. Paired arrays of colored squares were identical or differed in the color of one square, and in the latter case, the changed color was unique on that trial (item change) or was duplicated elsewhere in the array (color-location binding change). Children (8-10 and 11-12 years old) and older adults (65-85 years old) showed deficits relative to young adults. These were only partly simulated by dividing attention in young adults. The older adults had an additional deficiency, specifically in binding information, which was evident only when item- and binding-change trials were mixed together. In that situation, the older adults often overlooked the more subtle, binding-type changes. Some working memory processes related to binding undergo life-span development in an inverted-U shape, whereas other, bias- and salience-related processes that influence the use of binding information seem to develop monotonically. 相似文献
239.
Theorists have postulated that some variants of psychopathy result from childhood abuse and neglect. Dissociative symptoms are also thought to arise from abuse. To date, the conjoint associations among abuse, dissociation, and psychopathy have not been examined systematically. Some have hypothesized that abuse relates primarily to the affective symptoms of psychopathy, with dissociative experiences mediating this relationship. Others have suggested that abuse more directly affects the impulsive lifestyle features of psychopathy. The authors used structural equation modeling to examine these hypotheses in a sample of 615 male offenders who had completed a retrospective self-report measure of childhood abuse, the Dissociative Experiences Scale, and R. D. Hare's (2003) Psychopathy Checklist--Revised. Abuse exerted no direct or indirect effect on the core interpersonal and affective features of psychopathy but was directly related to the facet of psychopathy associated with an impulsive and irresponsible lifestyle. Implications for psychopathy subtypes are discussed. 相似文献
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The purpose of this study was to explore the validity, reliability, and generalizability of the Vedic Personality Inventory which consists of constructs derived from the Vedic literature of India. There were 57 participants (20 men, 37 women). The mean age was 44.3 yr. (SD= 15.1). The sample was predominantly older, well-educated women who volunteered to participate as respondees to invitations to participate posted in supermarkets, churches, colleges, and on the internet. Analysis yielded statistically significant correlations for scores on the Vedic Personality Inventory and on the Daily Spiritual Experiences Scale and the Brief Symptom Inventory, each of which measures domains of interest addressed by the first inventory. 相似文献