小鼠的记忆与脑内突触结构参数变化的相关性

比较不同月龄小鼠学习记忆力与脑内突触结构参数变化的相关性。选用１月龄和６月龄小鼠,用Ｙ－迷宫检测分辨学习能力,用一次性被动回避反应检测记忆力。然后杀鼠取脑,进行超微结构观察和定量分析测定。结果表明：（１）１月龄小鼠的分辨学习能力优于６月龄小鼠,记忆力也有优于６月龄小鼠的趋势。（２）无论在海马或大脑皮层体区,有两种结构参数有一致性增龄变化,即６月龄小鼠突触界面曲率都比１月龄小鼠显著和极显著增大;而６月龄小鼠上述两脑区的突触后致密物质厚度都极显著地小于１月龄小鼠。实验结果提示,脑内突触界面结构的增龄性变化可能是学习记忆力增龄性变化的结构基础。     

IRT中最小化χ2/EM参数估计方法

对IRT的双参数Logistic模型（2PLM）中未知参数估计问题,给出了一个新的估计方法――最小化χ2/EM估计。新方法在充分考虑项目反应理论(IRT)与经典测量理论(CTT)之间的差异的前提下,从统计计算的角度改进了Berkson的最小化χ2估计,取消了Berkson实施最小化χ2估计时需要已知能力参数的不合实际的前提,扩大了应用范围。实验结果表明新方法能力参数的估计结果与BILOG相比,精确度要高,且当样本容量超过2000时,项目参数的估计结果也优于BILOG。实验还表明新方法稳健性好     

Children Apply Principles of Physical Ownership to Ideas

Adults apply ownership not only to objects but also to ideas. But do people come to apply principles of ownership to ideas because of being taught about intellectual property and copyrights? Here, we investigate whether children apply rules from physical property ownership to ideas. Studies 1a and 1b show that children (6–8 years old) determine ownership of both objects and ideas based on who first establishes possession of the object or idea. Study 2 shows that children use another principle of object ownership, control of permission—an ability to restrict others’ access to the entity in question—to determine idea ownership. In Study 3 , we replicate these findings with different idea types. In Study 4 , we determine that children will not apply ownership to every entity, demonstrating that they do not apply ownership to a common word. Taken together, these results suggest that, like adults, children as young as 6 years old apply rules from ownership not only to objects but to ideas as well.     

Novelty as Opportunity and Risk: A Situated Cognition Analysis of Psychological Control and Novelty Seeking

Novel products present unknown opportunities as well as unknown risks. Past research suggested that low psychological control highlights risks and reduces the adoption of novel products. Consistent with a situated cognition perspective, we show that this depends on the specifics of low control. Across five studies, novelty seeking was lower after consumers thought about instances of low (vs. high) personal influence, but higher after consumers thought about instances of low (vs. high) predictability of the world. Thinking about a lack of personal influence increased the perceived importance of personal capability and in turn impaired the exploration of novel options, whereas thinking about an unpredictable world increased the perceived importance of preparedness for an unknown future and in turn the exploration of novel options. Throughout, perceiving low personal influence benefited familiar products, whereas seeing the world as unpredictable benefited novel products. This highlights that understanding consumers' responses to a lack of control requires joint consideration of the specifics of threat and task, consistent with situated cognition principles.     

MIRT模型中多维能力及其相关矩阵估计的影响因素

多维项目反应理论因其模型本身的天然优势及其兼具因素分析与项目反应理论于一身的优点,而被广大研究者及应用者所重视.本研究在前人研究基础上,重点讨论MIRT多维能力及能力间相关矩阵的参数估计问题.研究采用Monte Carlo模拟方法进行,在三因素完全随机设计（4 ×3×3）下,使用MCMC算法,探讨测验维度数、维度间的相关大小和测验项目数三个因素对MIRT能力及其相关矩阵估计的影响.     

A Longitudinal Investigation of Perceived Control and Cognitive Performance in Young,Midlife and Older Adults

ABSTRACT

Longitudinal associations between generalized control beliefs (one's perceived capacity to influence events) and cognitive test performance were examined in a population-based sample of young, midlife and older adults. Participants provided measures of perceived control, self-assessed health, education and depression and anxiety symptoms, and completed cognitive tests at two assessments, 4 years apart. For each age group, baseline (between-person) control was positively related to performance on tests of memory (immediate recall and digits backwards), speed (Symbol Digit Modalities Test and choice reaction time) and verbal intelligence (Spot-the-Word). Interaction effects indicated stronger associations of between-person control beliefs with indices of speed for the older age group relative to the younger groups. Within-person changes in control were not significantly associated with changes in cognitive test performance over the study interval. Implications of the findings for self-efficacy based interventions designed to promote cognitive functioning are discussed.     

Separating goals from behavioral control: Implications from learning predictive modularizations

The brain may be regarded as an anticipatory machine whose behavior strongly depends on its current predictive knowledge. Behavioral decision making depends on anticipated goal states as well as on the current internal motivations of the organism. Behavioral control, on the other hand, is guided by the goals currently chosen along with additional constraints. Both, decision making and control are thus anticipatory processes. Moreover, they are mutually dependent: while action control depends on currently selected goals, goal selection depends on achievability estimates, which must be based on the system's current action control competence. An autonomous, adaptive system thus faces the challenge of learning goal representations that are suitable for both, action selection and action control. We propose that a goal processing pathway should be separated from but also strongly interact with a sensorimotor control pathway. We investigate the encoding structures expectable along these two pathways for realizing effective and flexible action decision making and control. While the goal processing pathway needs to be able to distinguish motivation-oriented relevancies for decision making, the sensorimotor pathway needs to provide control-oriented encodings. We use an evolutionary machine learning technique to investigate how important modularity may be for realizing particular sensorimotor mappings. Next, we survey the results obtained by a neural network architecture, which show that enforcing multiplicative interactions between self-organizing sensorimotor control-oriented encodings and goal-oriented interaction selection encodings enables the learning of highly flexible decision making and action control structures. Furthermore, we show that the emerging goal-oriented encodings exhibit pre-linguistic compositional structures. We conclude that for bootstrapping higher-level cognitive capabilities it may be essential on the one hand to separate sensorimotor, anticipatory, control-oriented spatial encodings from compositional, goal-oriented spaces, and on the other hand to enable bidirectional, multiplicative interactions between these two sets of spatial encodings.     

Contextual Interference in Movements of the Same Class: Differential Effects on Program and Parameter Learning

Contextual interference effects in motor learning usually were not found when the tasks to be learned presumably required the same generalized motor program (GMP) and differed only with regard to the movement parameters (see Lee, Wulf, & Schmidt, 1992; Magill & Hall, 1990). Thus, tasks requiring different motor programs (e.g., different relative timings) seemed to be a prerequisite for random practice to be more effective than blocked practice. However, the previous studies (that did not find random/blocked differences) used global error measures that confounded errors in relative timing and errors in absolute timing. In the present study, subjects practiced three movement patterns that had the same relative timing (requiring the same GMP) but different overall durations (requiring different parameters). Errors in relative timing and in absolute timing were assessed separately. The results indicate that random practice is more effective for the learning of relative timing (GMP learning) and less effective for the learning of absolute timing (parameter learning) than blocked practice. Preliminary ideas as to the reasons for this effect are discussed.     

framing of prenatal screening test results and women's health-illness orientations as determinants of perceptions of fetal health and approval of amniocentesis

Abstract

Framing effects of medical test results and interactions of these effects with personal perspectives were investigated in the context of prenatal screening. Hundred and Thirty-three pregnant women undergoing the ‘triple-test’ were assessed as having health or illness orientations, and were randomly presented with reassuring/moderate/severe diagnoses framed in normal/abnormal terms, forming a 2 × 3 × 2 between subjects design. Evaluations of fetus' health and recommendations to perform amniocentesis were assessed. Findings showed healthier evaluations of the fetus and weaker recommendations to perform amniocentesis in normal versus abnormal framings. An interaction was found between framing, diagnosis, and personal orientations: women with health orientations receiving a moderate diagnosis framed in abnormal terms were significantly more inclined to recommend amniocentesis than illness-oriented women given the same diagnosis; the normal/abnormal framing of severe diagnoses yielded opposite effects on health-oriented versus illness-oriented women. The influences of framing effects and health/ illness orientations on health perceptions and behavioral intentions were discussed.     

Deus or Darwin: Randomness and belief in theories about the origin of life

A simple reminder of the fact that we do not always control life's outcomes reduced people's belief in Darwin's Theory of Evolution. This control-threat resulted in a relative preference for theories of life that thwart randomness, either by stressing the role of a controlling God (Intelligent Design) or by presenting the Theory of Evolution in terms of predictable and orderly processes. Moreover, increased preference for Intelligent Design over evolutionary theory disappeared when the latter was framed in terms of an orderly process with inevitable outcomes. Thus, psychological threat enhances belief in God, but only in the absence of other options that help to create order in the world.