视觉意识及其神经机制

视觉意识的神经机制是当前认知神经科学研究的热点问题之一。过去普遍认为视觉信息加工主要有两条通路:腹侧通路和背侧通路;而新近的研究表明还存在不经过初级视觉皮层(V1区)的第三条通路。高级视觉皮层、V1区和皮层下结构都对意识觉知的产生起到了相应的作用。已有的实验证据表明,意识的产生过程异常复杂,仍有很多问题值得继续深入讨论和研究。     

STROOP效应及其反转：无意识和意识知觉

该研究基于Stroop效应确立了意识知觉和无意识知觉间的质的差异,刺激特性(呈现时间)的改变和注意的改变引起了非常类似的行为上的质差模式,二者在决定意识时存在着补偿作用。当色词短暂呈现而被无意识知觉时,被试在对靶颜色进行命名时不能利用色词提供的预期信息,从而反应时出现典型的Stroop效应;而通过增强刺激特性或提高注意水平可以使色词被有意识知觉。从而出现了Stroop效应的反转。     

Dorsomedial prefrontal cortex 5-HT6 receptors regulate anxiety-like behavior

The dorsomedial prefrontal cortex (dmPFC) plays a very important role in decision-related and anxiety-related information processing. It has enriched 5-HT6 receptors; however, the precise role of dmPFC 5-HT6 receptors in anxiety remains to be fully investigated. In this study, we injected dmPFC with the 5-HT6 receptor agonist EMD 386088 and antagonist SB 271046 using stereotactic technology. 5-HT6 receptor activation in mice increased time spent in the center area on the open-field test, increased exploration of the open arms on the elevated plus maze test, and increased ratio on the social interaction test. 5-HT6 receptor inactivation induced the opposite effects. In brain slices, EMD 386088 decreased both spontaneous inhibitory postsynaptic currents (sIPSC) and spontaneous excitatory postsynaptic currents (sEPSC), while SB 271046 only increased sEPSC. These effects of EMD 386088 and SB 271046 could be reversed by the GABA_A receptor antagonist bicuculline (BMI) and positive allosteric modulator clonazepam (CLZ), respectively. Our results suggest that neurotransmission in the dmPFC by 5-HT6 receptor activation and inhibition may play an important role in anxiety-like behavior, and may provide new insight into the pathological mechanism and potential target of anxiety disorders.     

马克思主义哲学教学体系的形成与演变(上)

马克思并不是一个把哲学课题化、体系化的职业哲学家,而首先是一个革命家,是一个以实现无产阶级和人类解放为毕生使命的革命家。但是,以无产阶级和人类解放为理论主题,以形而上学批判、意识形态批判和资本批判为理论形式的马克思主义哲学,又的确存在着理论体系。马克思虽然     

Probability cuing of target location facilitates visual search implicitly in normal participants and patients with hemispatial neglect

We explored how variability in the probability of target locations affects visual search in normal individuals and in patients with hemispatial neglect, a deficit in attending to the contralesional side of space. Young and elderly normal participants responded faster when targets appeared in the more probable region than when targets appeared in the less probable region. Similarly, patients were sensitive to the distribution of targets, even in the neglected field. Although the attentional gradient that characterizes neglect was not eliminated, the response facilitation due to the probability distribution was proportionate to that of control participants and equal in magnitude across the neglected field. All participants exploited the uneven distribution of targets to enhance task performance without explicit instructions to do so or awareness of biases in their behavior. These results suggest that attentional orientation and sensitivity to external probabilities are possibly dissociable. An early sensory and a late motor mechanism are postulated as possibly being involved in the observed probability–matching behavior of participants.     

错误再认:意识、注意和刺激特性

该研究基于错误再认现象,确立了意识知觉和无意识知觉在行为结果上的质的差异。在决定一个刺激是被有意识知觉还是无意识知觉时,刺激特性和注意之间存在着相互补偿的作用。实验一表明,当一个刺激短暂呈现而被无意识知觉的时候,增强刺激特性或提高注意水平都能使它的知觉变为有意识的;相对应地,实验二表明,一个处于分散注意条件下被无意识知觉的刺激,也可以通过使注意集中或增强刺激特性而使它的知觉变为有意识的。该研究对意识、注意和刺激特性三者间的关系进行了讨论。     

意识和无意识知觉:注意和刺激特性间的相互补偿

该研究基于Exclusion任务,利用质的差异的研究范式,不仅确立了意识和无意识知觉在行为结果上的质的差异,而且发现刺激特性和注意在决定知觉意识时存在相互补偿的现象。在实验一中,当靶字短暂呈现时。被试用靶字补笔的比率高于基线水平;而当延长靶字呈现时间或提高对靶字的注意水平时,出现反转现象一用靶字补笔的比率低于基线水平。相对应地,在实验二中,分散注意条件下被试用靶字补笔的比率高于基线水平;而当注意集中或在分散注意条件下延长呈现时间时,出现了反转现象。     

Working memory and the guidance of visual attention: Consonance-driven orienting

Two experiments investigated the potential role of the content of working memory in guiding visual attention. Experiment 1 showed that maintaining a shape in working memory resulted in a decisive preference for moving attention to the same shape in the background when those shapes were task irrelevant. Experiment 2 showed a similar preference for words that were semantically related to an item held in working memory. We suggest that keeping an item active in working memory automatically results in a tendency for attention to be “attracted” to stimuli that are related to that item either visually or semantically.     

The implicit sociometer effect and the moderating role of relational self‐construal

The present study examined how negative feedback influenced implicit self‐evaluations and how individuals' level of relational self‐construal (RelSC) moderated these relationships. One hundred Chinese university students completed the relational‐interdependent self‐construal scale and were randomly assigned into one of three conditions (social exclusion, personal failure, or control). After receiving the manipulation, participants completed two Brief Implicit Association Tests (BIATs) that measured their implicit self‐liking and self‐competence. The results indicated that people with a highly RelSC typically had higher implicit self‐liking, but they decreased their implicit self‐liking more than those with a low RelSC after experiencing social exclusion. However, RelSC did not influence the effect of personal failure on implicit self‐liking. In addition, RelSC was not associated with implicit self‐competence in any situation.     

马克思主义哲学:我们时代的真理和良心——纪念马克思逝世130周年

一个伟大的哲学家、思想家逝世之后,对他的观点、思想和学说进行持续性研究在人类思想史不乏先例。但是,像马克思主义哲学这样在世界范围内引起如此广泛、深入而持久的研究却是罕见的。更重要的是,每当出现重大历史事件,每当历史处于转折关头,人们都不由自主地把目光转向马克思,并对马克思主义哲学进行新的研究。当然,我们注意到,在对马克思主义哲学不同维度、不同层