干扰、工作记忆与一般流体智力

工作记忆与复杂认知任务之间的关系已成为工作记忆研究领域的热点问题。大量研究表明,工作记忆广度不仅是评价工作记忆能力的一种指标,而且也是衡量一个人的高级认知能力的预报因子。本文从工作记忆的本质以及工作记忆与一般流体智力之问的关系人手,分析了干扰不仅是影响工作记忆容量个体差异的关键因素,而且也在工作记忆与一般流体智力的关系中起着重要的影响作用。     

合作数学问题解决与心理模型建构关系研究

合作学习研究者很早就开始关注合作互动中解释的作用。Chi关于自我解释的研究表明解释是一种非常有效果的学习现象,能够起到修补和建立学习者的心理模型的作用。本研究以28名高一学生为被试,采取了两种程序的合作学习任务,研究中虽然没有发现两种程序在问题解决结果上的显著差异,但是却表现出在心理模型建构方面互动效果上的差异,或表现为同等效果下的互动次数有显著性差异。     

阅读材料类型和难度对五年级儿童阅读策略的影响

以34名五年级儿童为被试,采用出声思维法考查了阅读材料类型和难度对儿童阅读策略使用情况的影响。结果发现,被试在记叙文阅读过程中使用的阅读策略种类数和总次数均多于说明文。阅读材料难度对于阅读策略种类数和使用次数没有影响。阅读材料类型和难度都对多个阅读策略的使用次数有影响,但是阅读材料类型和难度对于各阅读策略使用次数的影响并不一致。     

Profiling retirees in the retirement transition and adjustment process: examining the longitudinal change patterns of retirees' psychological well-being

The author used role theory, continuity theory, and the life course perspective to form hypotheses regarding the different retirement transition and adjustment patterns and how different individual and contextual variables related to those patterns. The longitudinal data of 2 samples (n(1) = 994; n(2) = 1,066) from the Health and Retirement Survey were used. Three latent growth curve patterns of retirees' psychological well-being were identified as coexisting in the retiree samples through growth mixture modeling (GMM) analysis. On the basis of the latent class membership derived from GMM, retiree subgroups directly linked to different growth curve patterns were profiled with individual (e.g., bridge job status) and contextual variables (e.g., spouse working status). By recognizing the existence of multiple retiree subgroups corresponding to different psychological well-being change patterns, this study suggests that retirees do not follow a uniform adjustment pattern during the retirement process, which reconciles inconsistent previous findings. A resource perspective is further introduced to provide a more integrated theory for the current findings. The practical implications of this study are also discussed at both individual level and policy level.     

Culture and group perception: dispositional and stereotypic inferences about novel and national groups

In 3 studies, the authors tested the hypothesis that Chinese participants would view social groups as more entitative than would Americans and, as a result, would be more likely to infer personality traits on the basis of group membership--that is, to stereotype. In Study 1, Chinese participants made stronger stereotypic trait inferences than Americans did on the basis of a target's membership in a fictitious group. Studies 2 and 3 showed that Chinese participants perceived diverse groups as more entitative and attributed more internally consistent dispositions to groups and their members. Guided by culturally based lay theories about the entitative nature of groups, Chinese participants may stereotype more readily than do Americans when group membership is available as a source of dispositional inference.     

Feature extraction via KPCA for classification of gait patterns

Automated recognition of gait pattern change is important in medical diagnostics as well as in the early identification of at-risk gait in the elderly. We evaluated the use of Kernel-based Principal Component Analysis (KPCA) to extract more gait features (i.e., to obtain more significant amounts of information about human movement) and thus to improve the classification of gait patterns. 3D gait data of 24 young and 24 elderly participants were acquired using an OPTOTRAK 3020 motion analysis system during normal walking, and a total of 36 gait spatio-temporal and kinematic variables were extracted from the recorded data. KPCA was used first for nonlinear feature extraction to then evaluate its effect on a subsequent classification in combination with learning algorithms such as support vector machines (SVMs). Cross-validation test results indicated that the proposed technique could allow spreading the information about the gait's kinematic structure into more nonlinear principal components, thus providing additional discriminatory information for the improvement of gait classification performance. The feature extraction ability of KPCA was affected slightly with different kernel functions as polynomial and radial basis function. The combination of KPCA and SVM could identify young-elderly gait patterns with 91% accuracy, resulting in a markedly improved performance compared to the combination of PCA and SVM. These results suggest that nonlinear feature extraction by KPCA improves the classification of young-elderly gait patterns, and holds considerable potential for future applications in direct dimensionality reduction and interpretation of multiple gait signals.     

早期应激对抑郁相关行为及神经内分泌反应的长期影响

临床研究发现,早期创伤性经历是导致成年抑郁症易感性增加的高风险因素之一。但早期应激通过何种途径对抑郁发病产生长期的影响,目前尚不清楚。本文综述了近年来有关的实验动物研究,从早期应激的动物模型建立、早期应激对成年动物抑郁相关行为及神经内分泌反应的长期影响等方面进行了系统论述和分析,进而提出了早期应激并不影响动物的本能行为,但早期应激影响与行为动机和应激应对等认知相关的行为的观点,进一步论证了早期应激是通过增加个体潜在的易患病素质对抑郁症发病产生影响     

Time-of-day effects on response of natural killer cells to acute stress in men and women.

Diurnal influences on natural killer (NK) cell changes to acute stress were assessed in 21 men and 21 women assigned to either an acute stress (mental arithmetic) or control task condition. Sessions began at either 8 a.m. or 2 p.m. Number of NK (CD3-CD56+) cells and NK activity were measured at baseline, during the 5-min task, and 60 and 90 min after the task. Both morning and afternoon stress participants had elevated NK cell numbers during the task. After the task, number of NK cells decreased in morning stress participants but remained significantly above baseline levels 60 and 90 min posttask. NK cell numbers in afternoon stress participants decreased to below baseline levels 60 and 90 min after the task. Changes in NK activity were driven primarily by diurnal influences. NK activity increased in all morning participants and stayed increased 60 and 90 min posttask. NK activity of all afternoon participants also increased during the task but dropped below baseline 60 and 90 min later. Greater increases in NK levels and activity during the task were associated with greater heart rate changes.