Effects of stress on nonassociative learning processes in male and female rats

In this study we assessed habituation and sensitization of the acoustic startle response (ASR) to discern whether intense, inescapable stress affects nonassociative learning differently in male and female rats. Rats were inescapably stressed 2 hours per day over 3 consecutive days. ASR magnitudes were measured at several times post-stress (1, 4, 8, and 15 days after cessation). Females generally showed greater ASR magnitudes (compared to males), but both sexes exhibited short and long-term habituation across the testing days. ASR magnitudes were only affected by stress in male subjects. The effect in males was an increase in short-term sensitization of the ASR on post-stress day-4. The results suggest that stressed males and females react differently to ASR testing, in that stress males appear to develop an exaggerated ASR response over repeated test sessions due to short-term sensitization. The source of the short-term sensitization is discussed with regards to possible stress-induced enhanced contextual learning during ASR testing on post-stress day-1.     

Cognition and Self-Control: Cognitive Control of Painful Sensory Input

Eighty Ss were first tested for base-level response to a pain-producing stimulus and then were re-tested on the same pain stimulus after receiving 1 of 8 experimental treatments. The 8 treatments were arranged in a 2 x 2 x 2 factorial design: presence or absence of hypnotic induction procedure; presence or absence of instructions for anesthesia; and presence or absence of demands for honest reports. Neither the hypnotic-induction procedure nor the demands for honesty affected the Ss'reports of the degree of pain experienced. The anesthesia instructions--"think of the hand as numb and insensitive as if it were a piece of rubber..."--produced an equal degree of pain reduction in hypnotic and non-hypnotic Ss and in Ss who were and those who were not exposed to demands for honesty. The results indicate that (a) Ss' reports of pain are less affected by demands for honesty and are more closely related to their actual experiences than has been previously assumed and (b) instructions which direct Ss to exercise cognitive control over painful sensory input are effective (with or without 'hypnosis') in reducing the experience of pain.     

Behavioral and neural predictors of upcoming decisions

Although it is widely known that brain regions such as the prefrontal cortex, the amygdala, and the ventral striatum play large roles in decision making, their precise contributions remain unclear. Here, we used functional magnetic resonance imaging and principles of reinforcement learning theory to investigate the relationship between current reinforcements and future decisions. In the experiment, subjects chose between high-risk (i.e., low probability of a large monetary reward) and low-risk (high probability of a small reward) decisions. For each subject, we estimated value functions that represented the degree to which reinforcements affected the value of decision options on the subsequent trial. Individual differences in value functions predicted not only trial-to-trial behavioral strategies, such as choosing high-risk decisions following high-risk rewards, but also the relationship between activity in prefrontal and subcortical regions during one trial and the decision made in the subsequent trial. These findings provide a novel link between behavior and neural activity by demonstrating that value functions are manifested both in adjustments in behavioral strategies and in the neural activity that accompanies those adjustments.     

Low doses of interleukin-1beta improve the leverpress avoidance performance of Sprague-Dawley rats

Recent research has indicated that the pro-inflammatory cytokines, particularly interleukin-1beta (IL-1beta), can affect learning and memory. We injected male Sprague-Dawley rats with IL-1beta (1.0, 3.0, or 6.0 microg/kg, i.p.) or saline vehicle, 24h before a single 4-h session of leverpress escape/avoidance conditioning. No effect of IL-1beta at any dose was observed in the number of escape responses across the 4-h session. However, subjects treated with the two lower doses (1.0 and 3.0 microg/kg) of IL-1beta performed more avoidance responses during the final hour of the 4-h session than the other two groups. Subjects treated with the highest dose of IL-1beta (6.0 microg/kg) did not differ from controls. Results are discussed in terms of the possible mechanisms behind the IL-1beta-induced enhancement of learning, as well as the observed dose-response relationship.     

Personality profiles and the prediction of categorical personality disorders

Personality disorders (PDs) are usually construed as psychiatric categories characterized by a unique configuration of traits and behaviors. To generate clinical hypotheses from normal personality trait scores, profile agreement statistics can be calculated using a prototypical personality profile for each PD. Multimethod data from 1,909 psychiatric patients in the People's Republic of China were used to examine the accuracy of such hypotheses in the Interpretive Report of the Revised NEO Personality Inventory. Profile agreement indices from both self-reports and spouse ratings were significantly related to PD symptom scores derived from questionnaires and clinical interviews. However, accuracy of diagnostic classification was only modest to moderate, probably because PDs are not discrete categorical entities. Together with other literature, these data suggest that the current categorical system should be replaced by a more comprehensive system of personality traits and personality-related problems.     

A differing bidirectional impact on the recognition accuracy of facial expression

This study explored a bidirectional impact on the recognition accuracy of various facial expressions deriving from both the observer and sender in a sample of Chinese participants. A facial manipulation task was used to examine the ability of an observer's facial feedback to modulate the recognition of various facial expressions. Furthermore, the effect of a sender's facial expression with an open or closed mouth on recognition accuracy was investigated. The results showed that only recognition accuracy of a sad facial expression was influenced simultaneously by bidirectional sources from a sender and observer. Moreover, the impact of the unidirectional cue of a sender's facial feature (i.e., mouth openness) on happy and neutral faces was found to influence the recognition accuracy of these faces, but not the observer's bodily state. These findings indicate that the bidirectional impact derived from an observer and sender on facial expression recognition accuracy differs for emotional and neutral expressions.     

当代大学生创业意向影响因素研究

为了深入了解当代大学生的创业意向及其影响因素,研究者以全国30所高校5000多名大学生为被试,对影响大学生创业意向的诸多因素进行了分析。研究发现:当代大学生的创业意向在性别、奖学金获得次数、学生干部经历、出生地上均存在一定差异。大学生主客观条件中的性别、学校性质、创业兴趣、创意能力改善对创业意向有显著影响。创业教育和创业环境认知的引入对于预测大学生的创业意向均有增量效度,能够在个体的主客观条件以外解释个体创业意向的变异。在大学生认知中,影响创业成功的因素主要由客观背景资源、主观能力经验和外部宏观环境3个因子组成,其中主观能力经验的作用排在首位。     

《管子》对《淮南子》的影响

《管子》对《淮南子》的影响,体现在文本和思想两个方面。《淮南子》中,既有对《管子》文本的袭用,也有对《管子》思想的继承。这与汉初的社会思潮和该书的编撰意图有关,也与淮南王刘安门下聚集了一部分来自齐地的学者有直接关系。