Dynamic modulation of an orientation preference map by GABA responsible for age-related cognitive performance

Accumulating evidence suggests that cognitive declines in old (healthy) animals could arise from depression of intracortical inhibition, for which a decreased ability to produce GABA during senescence might be responsible. By simulating a neural network model of a primary visual cortical (V1) area, we investigated whether and how a lack of GABA affects cognitive performance of the network: detection of the orientation of a visual bar-stimulus. The network was composed of pyramidal (P) cells and GABAergic interneurons such as small (S) and large (L) basket cells. Intrasynaptic GABA-release from presynaptic S or L cells contributed to reducing ongoing-spontaneous (background) neuronal activity in a different manner. Namely, the former exerted feedback (S-to-P) inhibition and reduced the frequency (firing rate) of action potentials evoked in P cells. The latter reduced the number of saliently firing P cells through lateral (L-to-P) inhibition. Non-vesicular GABA-release, presumably from glia and/or neurons, into the extracellular space reduced the both, activating extrasynaptic GABAa receptors and providing P cells with tonic inhibitory currents. By this combinatorial, spatiotemporal inhibitory mechanism, the background activity as noise was significantly reduced, compared to the stimulus-evoked activity as signal, thereby improving signal-to-noise (S/N) ratio. Interestingly, GABA-spillover from the intrasynaptic cleft into the extracellular space was effective for improving orientation selectivity (orientation bias), especially when distractors interfered with detecting the bar-stimulus. These simulation results may provide some insight into how the depression of intracortical inhibition due to a reduction in GABA content in the brain leads to age-related cognitive decline.     

情绪和框架效应对个体捐赠决策影响的实验研究

本研究采用双因素被试间实验具体考察了特定即时情绪和框架效应对于捐赠决策的影响,结果发现存在显著的主效应和交互作用。悲伤情绪能够增加捐赠者的捐赠意愿,快乐情绪会降低捐赠者的捐赠意愿;损失框架能够增加捐赠者的捐赠意愿,幸存框架会降低捐赠者的捐赠意愿;快乐情绪的捐赠者的捐赠决策受框架效应的影响要弱于中性情绪和悲伤情绪的捐赠者,捐赠者在幸存框架下的捐赠决策受情绪的影响比在损失框架下受情绪的影响更小。     

The effects of acute stress and perceptual load on distractor interference

Selective attention can be improved under conditions in which a high perceptual load is assumed to exhaust cognitive resources, leaving scarce resources for distractor processing. The present study examined whether perceptual load and acute stress share common attentional resources by manipulating perceptual and stress loads. Participants identified a target within an array of nontargets that were flanked by compatible or incompatible distractors. Attentional selectivity was measured by longer reaction times in response to the incompatible than to the compatible distractors. Participants in the stress group participated in a speech test that increased anxiety and threatened self-esteem. The effect of perceptual load interacted with the stress manipulation in that participants in the control group demonstrated an interference effect under the low perceptual load condition, whereas such interference disappeared under the high perceptual load condition. Importantly, the stress group showed virtually no interference under the low perceptual load condition, whereas substantial interference occurred under the high perceptual load condition. These results suggest that perceptual and stress related demands consume the same attentional resources.     

授权赋能领导行为对员工内部人身份感知的影响:基于组织的自尊的调节作用

从组织投资的视角,研究授权赋能领导行为、内部人身份感知与组织公民行为之间的关系.通过问卷调查,搜集了一家企业146名主管和下属的配对数据.研究结果表明,领导授权赋能行为对员工内部人身份感知有积极的影响作用,同时,内部人身份感知在授权赋能领导行为和员工组织公民行为之间起到完全中介作用,同时,员工基于组织的自尊对内部人身份感知的中介效应起到调节作用.最后还讨论了未来的研究方向和实际应用的意义等内容.     

临床胜任能力——以重症医学科医生面临的挑战为例

随着重症医学的发展,我国重症医学科医生临床胜任能力将面临着巨大挑战;他们不仅需要具备精湛的临床技术,同样重要的是还需要具备高超的合作、沟通能力,充沛的精力和体力,丰满的人文和哲学素养,以及终身的知识更新和实践能力提高.     

Does high memory load kick task-irrelevant information out of visual working memory?

The limited capacity of visual working memory (VWM) requires the existence of an efficient information selection mechanism. While it has been shown that under low VWM load, an irrelevant simple feature can be processed, its fate under high load (e.g., six objects) remains unclear. We explored this issue by probing the “irrelevant-change distracting effect,” in which the change of a stored irrelevant feature affects performance. Simple colored shapes were used as stimuli, with color as the target. Using a whole-probe method (presenting six objects in both the memory and test arrays), in Experiment 1 we found that a change to one of the six shapes led to a significant distracting effect. Using a partial-probe method (presenting the probe either at the screen center or at a location selected from the memory array), in Experiment 2 we showed the distracting effect again. These results suggest that irrelevant simple features can be stored into VWM, regardless of memory load.     

Serum levels of brain-derived neurotrophic factor (BDNF), BDNF gene Val66Met polymorphism, or plasma catecholamine metabolites, and response to mirtazapine in Japanese patients with major depressive disorder (MDD)

Object We investigated an association between the polymorphism of brain-derived neurotrophic factor (BDNF) gene Val66Met and the response to mirtazapine in Japanese patients with major depressive disorder (MDD). We also examined mirtazapine's effects on the serum BDNF and plasma levels of catecholamine metabolites in these patients. METHODS: Eighty-four patients who met the DSM-IV-TR criteria for MDD were treated with only mirtazapine for 4 weeks. The BDNF Val66Met polymorphism was detected by direct sequencing in the region, and serum BDNF levels and plasma levels of catecholamine metabolites were measured by ELISA and HPLC-ECD, respectively. RESULTS: Mirtazapine treatment for 4 weeks significantly increased serum BDNF levels in the responders, whereas nonresponders showed significant decreases. No association was found between either of the two genotypes (Val/Val vs. Met-carriers) and the response to mirtazapine at T4 or the serum BDNF levels at T0. Mirtazapine did not alter the plasma levels of homovanillic acid (HVA) or 3-methoxy-4-hydroxyphenylglycol (MHPG). Discussion The dynamics of serum BDNF levels, but not plasma levels of HVA and MHPG, reflect the response to mirtazapine treatment; the BDNF Val66Met polymorphism in patients with depression is, however, associated with neither a particular response to mirtazapine treatment nor baseline serum BDNF levels. Conclusion Serum BDNF levels, but not plasma levels of HVA or MHPG, and BDNF Val66Met polymorphism are related to the mirtazapine response in MDD.     

当代生态危机的认识论根源及出路

对自然的数学化必然导致人类对自然的对象化思维,从而把自然当作可以加以征服和驾驭的对象物;近代以来科学技术的成功运用更是助长了人类对自然的狂妄,误认为以人类有限的智慧能认识自然的无限奥秘。这是造成当代全球性生态危机的认识论根源。因此,为了走出当代生态危机,人类必须深刻认识到自己认识的有限性,找回“有学识的无知”,从而对无限的终极实在保持应有的敬畏之感。     

非熟练潮-粤双言者的语义通达：来自听觉词加工的证据

采用听觉跨语言启动的语义判断范式, 考察非熟练潮-粤双言者的两种方言之间的语义通达方式。结果发现, 无论是以潮语词为启动词, 还是以粤语词为启动词, 当二者具有翻译关系时, 启动词均促进对目标词的识别, 但L1对L2的启动量比L2对L1的启动量大。当启动词与目标词具有语义联想关系时, 启动词亦能促进对目标词的识别, 但L1→L2与L2→L1的启动量差异不显著。整个研究表明, 非熟练潮-粤双言者的两种方言的词汇独立表征, 语义共享表征; 第二方言的词汇能够直接通达语义表征, 不需要以第一方言的词汇为中介, 但双言的词汇表征与语义表征的联结强度仍然存在着不对称性。     

方言与普通话并用:双言心理研究述评

由于汉语方言的复杂性和多年来的推广普通话,使得方言和普通话并用的双言现象非常普遍.在语言关联性假设的指引下,心理学家探讨了双言者的语言表征,考察了双言对于双言者的记忆、时间认知和语言加工的影响,调查了双言者的语言态度,包括两种语言的语用情况和内隐态度.未来研究要继续关注双言者的语言表征及其提取机制,探查双言现象的认知神经机制,进一步深入探讨双言对双言者心理的影响.