Visual memory decay is deterministic

After observers see an object or pattern, their visual memory of what they have seen decays slowly over time. Nearly all current theories of vision assume that decay of short-term memory occurs because visual representations are progressively and randomly corrupted as time passes. We tested this assumption using psychophysical noise-masking methods, and we found that visual memory decays in a completely deterministic fashion. This surprising finding challenges current ideas about visual memory and sets a goal for future memory research: to characterize the deterministic "forgetting function" that describes how memories decay over time.     

Adrenocortical reactivity and social competence in seven year-olds

We examined temporal changes in salivary cortisol in response to a peer self-presentation task in a group of seven year-olds, some of whom scored high, average, and low on the Harter, 1983 Perceived Social Competence Scale. Salivary cortisol was measured pre-task, and 20 and 35 min post-task. We found a significant relation between individual differences in perceived social competence and salivary cortisol reactivity in response to the task. Children who perceived themselves as socially competent exhibited a significantly greater decrease in salivary cortisol from 20 to 35 min following the task compared with children who self-reported a relatively lower degree of social competence. We speculate on the meaning of salivary cortisol changes in childrens socio-emotional development.     

Risk of sexual revictimization: A theoretical model

Survivors of child sexual abuse suffer serious short- and long-term psychological consequences. Sexual revictimization as an adult is one of the consequences that has been reported. At present, there is no theoretical model identifying the risk factors that result in child sexual abuse survivors being at greater risk of experiencing an adult sexual assault. The proposed model is designed to integrate existing research, stimulate further empirical work, and eventually aid in the development of a program to prevent revictimization. The variables hypothesized to play a mediating role in the pathway to revictimization include: severe psychological symptoms as a consequence of the child sexual abuse, poor coping styles, an insecure attachment style, hyperfemininity, delinquent behavior, drug use, and high risk sexual behavior.     

Factor Structure of the School Reinforcement Survey Schedule: School Is More Than Grades

The School Reinforcement Survey Schedule (SRSS) was administered to 5913 4th through 12th graders as part of an evaluation component of the University of South Carolina's Institute for Families in Society's School-Based Mental Health Project. A factor analysis of SRSS responses yielded six interpretable factors. Gender differences in responses showed that girls, as opposed to boys, find a wider variety of reinforcers associated with school to be pleasurable. A significant, but small, correlation was found between grades and school reinforcement.     

Attraction to a dissimilar stranger as a function of level of effectance arousal

An experiment was carried out to demonstrate that the relationship between attitudes of a stranger and attraction to that stranger can be mediated by effectance arousal and the consequent information search to reduce the arousal. The argument posited was that individuals under high effectance arousal produced by a confusing and ambiguous film would be attracted to dissimilar others as a source of information and uncertainty reduction. Results indicated that high levels of arousal produced greater attraction to a dissimilar stranger than to a similar stranger. This finding was reversed when an explanation was provided along with the confusing film, lending support to the uncertainty reduction position.     

父母心理控制与小学生的欺负行为:敌意归因和冷酷无情的作用检验

采用班级整群抽样法选取1847名3~6年级小学生（男生987名;平均年龄10.73±1.16岁）及其家长为被试,采用问卷法考察父母心理控制与小学生欺负行为的关系,同时探讨敌意归因和冷酷无情的中介作用。结果发现：（1）父母心理控制显著正向预测小学生的欺负行为;（2）冷酷无情在父母心理控制与小学生欺负行为间的关系中存在中介作用,敌意归因不发挥中介作用;（3）父母心理控制对小学生欺负行为影响的中介机制不存在显著的性别差异和学段差异。本研究结果表明,冷酷无情是父母心理控制影响小学生欺负行为的重要机制,但敌意归因不是。研究者和实践者应注重对欺负者情感加工能力的关注和干预。     

Automated assessment of conditioning parameters for context and cued fear in mice

A behavioral technique often used to evaluate the cognitive performance of rats and mice is the fear conditioning paradigm. During conditioned fear experiments, freezing responses shown by rodents after exposure to environmental stimuli previously paired to an aversive experience provide a behavioral index of the animal's associative abilities. The present study examined the ability of a computer-controlled automated Freeze Monitor system for recording immobility behavior in mice. The sensitivity of the automated procedure to detect group differences caused by the application of various training protocols was also evaluated. Statistical analyses revealed significant positive correlations between immobility scores obtained with the automated apparatus and hand-scored data collected by a continuous or a time-sampling method. Behavioral patterns recorded by the computerized system were very similar to those obtained by the hand-scoring methods adopted. In particular, during context testing, exposure to environmental stimuli previously paired with a mild foot shock (unconditioned stimulus [US]) evoked increased immobility behavior in mice conditioned with the US compared with levels of immobility displayed by mice previously confined to the same contextual stimuli without receiving the US. Moreover, although during conditioned stimulus (CS) testing, mice previously exposed to the US displayed high levels of immobility when confined to environmental cues much different from those paired with the US (contextual fear generalization), both hand-scored and automated results revealed the effect of CS–US pairing (increased immobility) only in mice trained to associate the two stimuli (paired group) but not in mice exposed to both CS and US separated by a 40-sec time interval (unpaired group) or in mice receiving only the US (US group) during conditioning sessions. Overall, the results show associative conditioning measured in an automated apparatus and highlight the utility of obtaining both latency as well as beam interruption parameters.     

冠心病的介入治疗——药物洗脱支架还是裸支架？

冠心病的治疗包括多种方式,在强化内科保守治疗的基础上,采用经皮冠状动脉介入治疗既可以改善患者的生活质量又能降低病死率。介入治疗中最重要的方式是支架植入。但应用药物洗脱支架,还是普通金属裸支架一直是近两年来的争论焦点。BASKET-LATE研究的发布,更给药物洗脱支架的应用蒙上了可怕的阴影。就我们现阶段的实际临床应用而言,只要服用足够长的至少双联抗小血板药物治疗,药物洗脱支架的应用还是安全的,而且临床主要心血管事件较裸支架明显降低。     

早产儿预防性应用抗生素的临床决策思路

近年来,随着对滥用抗生素所引起的细菌耐药性和二重感染的认识的逐步深入,预防性应用抗生素在临床上越来越受到限制.但由于早产儿感染的临床隐匿性和易并发严重并发症等特点,预防早产儿感染的发生和进一步的发展,就显得尤为重要.通过对早产儿发生感染的易感因素、感染诱因和临床特点的分析研究,来探讨早产儿临床预防应用抗生素的必要性、合理性及临床决策思路.