Shoulder Joint Position Sense Improves With External Load

Joint position sense (JPS) is important in the maintenance of optimal movement coordination of limb segments in functional activities. Researchers have shown that the sensitivity of musculotendinous mechanoreceptors increases as muscle activation levels increase. In the present study, when 25 participants tried to replicate the same presented position, both vector and elevation angle repositioning errors decreased linearly as the external load increased up to 40% above unloaded shoulder torque. However, external load had no effect on plane repositioning error. The results indicated that JPS increased under conditions of increasing external load but only in the direction of the applied load. That finding indicates that JPS acuity improves as muscle activation levels increase.     

A Cerebral Hyperventilation Index for Electroencephalography

This study was an attempt to determine the effect of drive on probability learning. Each of two groups of Ss was divided into high- and low-drive groups on the basis of MAS scores. Each S was given 200 trials on a probability learning task, with 70 per cent reinforcement on one side and 30 per cent reinforcement on the other. At the .05 level, there was no difference between groups in probability choices, and neither group differed from the objective probability scores. The results are discussed in terms of the number of trials involved, the introduction of emotional arousal, and Hullian theory. On the basis of a comparison with the results of previous studies, it was suggested that investigators be cautious in generalizing probability learning results from one species to another.     

Facial expressions can inhibit the activation of gender stereotypes

ABSTRACT

Using faces as the priming stimuli, the present study explored the influence of facial expressions on the activation of gender stereotypes using a lexical decision paradigm. Experiment 1 explored the activation of gender stereotypes when the facial primes contained only gender information. The results showed that gender stereotypes were activated. In Experiment 2, the facial primes contained both gender category and expression information. The results indicated that gender stereotypes were not activated. Experiment 3 required the participants to make emotion, gender, or impression decisions concerning the facial primes before the lexical decision task. The results showed that gender stereotypes were not activated in emotion and impression decisions conditions, whereas stereotypes were activated in gender decisions condition. These finding suggest that facial expressions can inhibit automatic activation of gender stereotypes, unless the perceivers perform gender categorization processing to prime faces intentionally.     

Mood-congruent false memories in the DRM paradigm

This study investigated the creation of mood-congruent false memories within the Deese–Roediger–McDermott (DRM) paradigm using recall and recognition of critical lures as performance measures. Participants (n=93) were randomly assigned to three mood-induction conditions (positive, negative and control) and were presented with positive, negative and neutral DRM word lists in audio form. We predicted that intrusion errors of the critical lures would be higher in the mood-congruent conditions. Results confirmed this prediction and extended previous DRM research by showing that already high false memory rates were increased when the valence of the lures matched the mood-induction condition. Furthermore, participants made more “remember” judgements for the emotion critical lures in their mood-congruent conditions. Discussion draws on spreading activation explanations of DRM findings, and considers how moods could increase activation of non-presented information.     

Impact of negative affectively charged stimuli and response style on cognitive-control-related neural activation: An ERP study

The canonical AX-CPT task measures two forms of cognitive control: sustained goal-oriented control (“proactive” control) and transient changes in cognitive control following unexpected events (“reactive” control). We modified this task by adding negative and neutral International Affective Picture System (IAPS) pictures to assess the effects of negative emotion on these two forms of cognitive control. Proactive and reactive control styles were assessed based on measures of behavior and electrophysiology, including the N2 event-related potential component and source space activation (Low Resolution Tomography [LORETA]). We found slower reaction-times and greater DLPFC activation for negative relative to neutral stimuli. Additionally, we found that a proactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during actively maintained previously cued information and that a reactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during just-in-time environmentally triggered information. This pattern of results was evident in relatively neutral contexts, but in the face of negative emotion, these associations were not found, suggesting potential response style-by-emotion interaction effects on prefrontal neural activation.     

Goal‐Proximity Decision‐Making

Reinforcement learning (RL) models of decision‐making cannot account for human decisions in the absence of prior reward or punishment. We propose a mechanism for choosing among available options based on goal‐option association strengths, where association strengths between objects represent previously experienced object proximity. The proposed mechanism, Goal‐Proximity Decision‐making (GPD), is implemented within the ACT‐R cognitive framework. GPD is found to be more efficient than RL in three maze‐navigation simulations. GPD advantages over RL seem to grow as task difficulty is increased. An experiment is presented where participants are asked to make choices in the absence of prior reward. GPD captures human performance in this experiment better than RL.     

Temperature-dependent crack surface tension

The fracture surface energy is calculated for a one-dimensional, exactly solvable model of a crack. The temperature dependence of the crack surface tension is determined on the basis of a self-consistent Einstein approach. It is found that lattice vibrations result in a strong reduction in the crack surface tension.     

视觉词汇加工的动态神经网络及其形成

揭示大脑加工的神经网络机制成为认知神经科学研究的最新取向.本研究以视觉词汇加工脑区(VWFA)的神经功能作为切入点,探讨视觉词汇加工神经网络的动态机制及其形成.研究一考察VWFA在刺激驱动和任务调节下的动态激活,及其与语音、语义脑区所组成神经网络的动态机制.研究二通过跨文化对比以及儿童阅读发展研究,阐明语言经验对视觉词汇加工网络的塑造作用.研究三对比功能网络、静息网络以及白质纤维束联结,探讨视觉词汇加工网络的动态联结及其形成.研究结果有助于建构视觉词汇加工的神经生理模型,为基于脑科学的阅读教学和阅读障碍矫治奠定理论基础,为认知神经科学研究提供了新的思路.     

Preconscious effects of temporary goals on attention

Two experiments examined whether accessible goals preconsciously direct selective attention. Goal activation was manipulated by one's goal pursuit being either undermined or affirmed (resulting in an experienced state of either incompleteness or completeness). Attention responses were assessed through a Stroop-like task (Experiment 1) and a response-time task in which participants indicated a stimulus' direction of motion (Experiment 2). Results showed that when goals were accessible, attention was drawn toward goal-relevant items—even when these items were to be ignored and when responses occurred too fast for conscious control. Accessible goals directed implicit cognition (i.e., attention toward stimuli associated with the goal), despite the fact that these goals were not chronically held, but manipulated in the lab.     

创造性的生理研究新进展

创造性的生理基础很复杂。关于创造性生理基础的研究集中在大脑皮质激活与脑半球不对称两个方面。研究发现,大脑皮质激活状态对创造性有影响,低水平的皮质激活,特别是低水平的前额叶激活,较有利于创造性．研究还发现,创造性和左右半球不对称活动有关,处于创造状态时,右半球相对要比左半球激活程度更高。