Rapid word learning under uncertainty via cross-situational statistics

There are an infinite number of possible word-to-word pairings in naturalistic learning environments. Previous proposals to solve this mapping problem have focused on linguistic, social, representational, and attentional constraints at a single moment. This article discusses a cross-situational learning strategy based on computing distributional statistics across words, across referents, and, most important, across the co-occurrences of words and referents at multiple moments. We briefly exposed adults to a set of trials that each contained multiple spoken words and multiple pictures of individual objects; no information about word-picture correspondences was given within a trial. Nonetheless, over trials, subjects learned the word-picture mappings through cross-trial statistical relations. Different learning conditions varied the degree of within-trial reference uncertainty, the number of trials, and the length of trials. Overall, the remarkable performance of learners in various learning conditions suggests that they calculate cross-trial statistics with sufficient fidelity and by doing so rapidly learn word-referent pairs even in highly ambiguous learning contexts.     

Effects of Father-Adolescent and Mother-Adolescent Relationships on Depressive Symptoms among Chinese Early Adolescents

Parent–adolescent relationships play an important role in protecting adolescents from depressive symptoms. However, there are no consistent conclusions about the extent to which fathers and mothers uniquely contribute to adolescents’ depressive symptoms. The present study aimed to acquire knowledge in this research area in two ways. First, this study separated the potential impacts of father–child and mother–child relationships on depressive symptoms in Chinese adolescents. Second, this study used a longitudinal design with nationally representative samples from the China Education Panel Survey. A total of 8794 middle school students in grade 7 completed measures of father–adolescent and mother–adolescent relationships, and depressive symptoms twice (T1 and T2; one-year interval). Results indicated that both positive father–adolescent and mother–adolescent relationships had negative effects on depressive symptoms in female adolescents. However, positive father-adolescent, not mother-adolescent, relationships had a negative effect on depressive symptoms in male adolescents. These findings suggest that positive parent–adolescent relationships could reduce early adolescents’ depressive symptoms, but positive father–adolescent and mother–adolescent relationships might have different protective effects on early adolescents’ depressive symptoms among male and female adolescents in China.

     

冲突世界中的和谐对话——老子和谐观给世人的提示

我们来到老子晚年定居讲学地区的西安,参加此次以"和谐世界,以道相通"为主题的"国际道德经论坛",其重要意义之一,便是会聚东西方学者,借老子的智慧来为我们当前扰攘不安的世界进行一次盛大的文化与哲学对话。我曾多次出席西安举办的老子学术讨论会,此次论坛国际学者的对话,要比以往更具有时代性意义。下面我想对老子思想的现代意义略作论述。     

Factors influencing readability of rapidly presented text segments

Experiment 1 compared paragraph comprehension for texts shown either as normal pages on a computer terminal screen or as rapid serial visual presentations (RSVPs) of small text segments to a common location. Over several days of practice, reading comprehension was equivalent in the normal presentation mode and the RSVP format. When successive RSVP segments contained some information in common, to mimic the experience of successive parafoveal and foveal views of words in normal reading, comprehension was somewhat worse than when successive segments contained no overlapping information. Experiment 2 used a variety of segment size and segment duration combinations to investigate the optimal means of presenting text in the RSVP format. Across a variety of presentation rates and text difficulties, comprehension was maximal for segments averaging about 12 character spaces in length. In Experiment 3, texts were divided into short idea units or into random segments of equal average length. Comprehension was shown to be greater in the structured condition than in the random condition. An optimal means of presenting text in the RSVP format could be superior to normal presentation methods for reading and other text-processing tasks.     

个体对效价预期和风险评估的时程加工机制:来自ERP的证据

采用事件相关电位技术(ERP),通过简单赌博任务,操纵结果预期的效价(输或赢)与风险(高风险与低风险),考察了个体对结果预期阶段的效价和风险评估的脑内时程动态加工过程。脑电结果发现:(1)在N2成分上,结果预期的效价主效应显著,预期输比预期赢能够引起更大的N2波幅;结果预期的风险主效应不显著。(2)在N500成分上,效价与风险之间的交互作用边缘显著,进一步简单效应分析发现,在预期输的条件下,肯定会输的N500波幅显著大于可能会输;而在预期赢的条件下,肯定会赢与可能会赢之间的N500波幅差异不显著。这说明,在不确定决策过程中的结果预期阶段,个体可能先对结果预期的效价进行加工,然后再对风险进行评估。     

Stress induces glucocorticoid-mediated apoptosis of rat Leydig cells in vivo

Stress can disrupt endocrine signalling in the male reproductive axis through high concentrations of glucocorticoids, the hallmark of stress. Our previous work revealed that a stress level of exogenous glucocorticoids could induce apoptosis of rat Leydig cells, which are the primary source of testosterone. The aim of this study was to investigate whether stress can induce apoptosis in rat Leydig cells in vivo and, if so, whether the process is the result of a direct effect of glucocorticoids. In a chronically stressed rat model, serum corticosterone concentration was increased significantly whereas serum testosterone was decreased. The frequency of apoptotic Leydig cells in stressed rats was also increased. Adrenalectomised rats subjected to chronic stress showed an elevated serum testosterone, while the apoptotic frequency of Leydig cells was not increased. It was established that glucocorticoid-induced Leydig cell apoptosis is mediated by glucocorticoid receptors (GRs), which translocate from cytoplasm to nucleus. Adenovirus microRNA-induced downregulation of GR expression in vitro alleviated the corticosterone-induced increase in apoptosis of Leydig cells. These results indicate that the stress-induced increase in corticosterone secretion resulted in apoptosis in rat Leydig cells in vivo, and thereby decreased testosterone synthesis.     

Active coping with stress suppresses glucose metabolism in the rat hypothalamus

We used 18F-fluorodeoxyglucose small-animal positron-emission tomography to determine whether different styles of coping with stress are associated with different patterns of neuronal activity in the hypothalamus. Adult rats were subjected to immobilization (IMO)-stress or to a non-immobilized condition for 30 min, in random order on separate days, each of which was followed by brain-scanning. Some rats in the immobilized condition were allowed to actively cope with the stress by chewing a wooden stick during IMO, while the other immobilized rats were given nothing to chew on. Voxel-based statistical analysis of the brain imaging data shows that chewing counteracted the stress-induced increased glucose uptake in the hypothalamus to the level of the non-immobilized condition. Region-of-interest analysis of the glucose uptake values further showed that chewing significantly suppressed stress-induced increased glucose uptake in the paraventricular hypothalamic nucleus and the anterior hypothalamic area but not in the lateral hypothalamus. Together with the finding that the mean plasma corticosterone concentration at the termination of the IMO was also significantly suppressed when rats had an opportunity to chew a wooden stick, our results showed that active coping by chewing inhibited the activation of the hypothalamic-pituitary-adrenal axis to reduce the endocrine stress response.     

Overall Hedonic Evaluations and Evaluation of Specific Moments from Past Relationships and High School Days

Two studies were conducted in which student participants gave overall hedonic evaluations of past relationships or their high school days, and, additionally, gave similar evaluations of the best, most memorable, worst, initial, and final moments from them. They also evaluated a typical moment and the percentages of good and bad times in these experiences. Such results from some individuals were given to other participants, who were also asked to make overall evaluations. Overall, the overall evaluations of the original participant related weakly rather than strongly to the evaluations of the specific moments. Generally, the other participants’ overall evaluations converged on those of the original recalling participants, but their overall evaluations of the past relationships were more positive than either their own initial evaluations or those of the original, recalling respondents. In sum, overall evaluations of these long, diverse experiences were not well predicted from valuations of the specific moments we investigated. Hedonic evaluations of past experiences may be influenced by appraisals of their success.     

Distinct processing for pictures of animals and objects: evidence from eye movements

Many studies have suggested that emotional stimuli orient and engage attention. There is also evidence that animate stimuli, such as those from humans and animals, cause attentional bias. However, categorical and emotional factors are usually mixed, and it is unclear to what extent human context influences attentional allocation. To address this issue, we tracked participants' eye movements while they viewed pictures with animals and inanimate images (i.e., category) as focal objects. These pictures had either negative or neutral emotional valence, and either human body parts or nonhuman parts were near the focal objects (i.e., context). The picture's valence, arousal, position, size, and most of the low-level visual features were matched across categories. The results showed that nonhuman animals were more likely to be attended to and to be attended to for longer times than inanimate objects. The same pattern held for the human contexts (vs. nonhuman contexts). The effects of emotional valence, category, and context interacted. Specifically, in images with a negative valence, focal animals and objects with human context had comparable numbers of gaze fixations and gaze duration. These results highlighted the attentional bias to animate parts of a picture and clarified that the effects of category, valence, and picture context interacted to influence attentional allocation.     

Natural ambiguities: Racial categorization of multiracial individuals

Understanding the perception of multiracial persons is increasingly important in today's diverse society. The present research investigated the process of categorizing multiracial persons as “Multiracial.” We hypothesized that perceivers would make fewer Multiracial categorizations of multiracials and that these categorizations would take longer than monoracial categorizations. We found support for these hypotheses across six experiments. Experiment 1 demonstrated that perceivers did not categorize morphed Black–White faces as Multiracial with the same frequency with which they categorized Black and White faces as Black and White (respectively), and that categorizations of multiracials as Multiracial took longer than monoracial categorizations. Experiment 2 replicated and extended these effects to real Black–White faces. Experiment 3 showed that these findings generalized to Asian–White faces. We used pixel variance analysis to show that these effects were not due to increased variance among Multiracial faces. The image analysis showed that the Black–White morphs and real biracials were actually less varied than either the Black or White sets of faces. Experiments 4 and 5 demonstrated that cognitive load and time constraints detrimentally affected multiracial, but not monoracial, categorizations. Experiment 6 showed that imbuing monoracial categories with importance decreases the use of the Multiracial category. Implications of these findings for understanding perceptions of multiracial persons are discussed.