The Occipital Cortex in the Blind

ABSTRACT— Studying the brains of blind individuals provides a unique opportunity to investigate how the brain changes and adapts in response to afferent (input) and efferent (output) demands. We discuss evidence suggesting that regions of the brain normally associated with the processing of visual information undergo remarkable dynamic change in response to blindness. These neuroplastic changes implicate not only processing carried out by the remaining senses but also higher cognitive functions such as language and memory. A strong emphasis is placed on evidence obtained from advanced neuroimaging techniques that allow researchers to identify areas of human brain activity, as well as from lesion approaches (both reversible and irreversible) to address the functional relevance and role of these activated areas. A possible mechanism and conceptual framework for these physiological and behavioral changes is proposed.     

浅谈内隐社会认知的研究与现状

内隐社会认知是无意识思想、认知理论和社会心理研究日渐整合的结果。作为认知心理学研究的一个组成部分,内隐社会认知的研究从方法论上,得益于内隐记忆研究中逐步完善的间接测量方法;从内容上,尽管内隐社会认知的研究还比较初浅,但却已经涵盖了社会认知、社会态度以及归因评价的多个方面。     

印象整饰与内隐态度效应

运用内隐联想测验对不同印象整饰水平个体的内隐态度进行了研究。结果表明：不同自我监控者的内隐性态度是存在的,高自我监控者的内隐态度和外显态度存在分离。研究对“印象整饰对强迫服从后态度改变的影响”的结果做出解释：自我监控者强迫服从后的态度中庸是其关注自身的公众形象而有意压抑和控制其内隐性的评价造成的。     

论述理解中逻辑有效与逻辑无效条件推理的研究

句法理论和心理模型理论是解释论述理解中逻辑有效 (如MP)与逻辑无效 (如AC)条件推理机制的两种不同观点。本研究通过两项实验旨在对这两种理论加以检测。实验要求被试阅读遵循MP或AC形式的故事后对故事结论的正确性做出判断。结果表明 ,在论述理解中 ,条件前提的语义联系强度影响MP推理 ;深思熟虑对MP和AC推理均产生影响。研究结果支持心理模型理论。     

中等强度情绪性图片的神经机制——一项fMRI研究

采用修订后的中等唤起度的国际情绪图片为刺激材料,以12名女性大学生为被试,考察情绪性图片引起的脑激活模式。结果发现,与中性条件相比,消极情绪图片激活了枕叶、杏仁核、海马旁回和壳核。积极情绪图片引起枕叶、内侧眶额、额中回等脑区的激活,研究结果再次验证了杏仁核与消极情绪的密切关系,同时推测,内侧眶额可能是中等唤起度的趋近性积极情绪的一个脑功能区。     

Re-emergence of extinguished auditory-cued conditioned fear following a sub-conditioning procedure: effects of hippocampal and prefrontal tetanic stimulations

Post-extinction exposure of rats to a sub-conditioning procedure can evoke conditioned fear, which may correspond to fear return and/or fear learning potentiation. The aim of the present study was to clarify this issue and examine the effects of tetanic stimulation of the hippocampus (HPC) and medial prefrontal cortex (mPFC), two brain regions implicated in post-extinction modulation of conditioned fear. Rats were initially submitted to five tone-shock pairings with either a 0.7-mA or 0.1-mA shock. Tone-evoked freezing was observed only with the higher shock intensity, indicating that the 0.1-mA shock corresponded to a sub-conditioning procedure. All conditioned rats underwent fear extinction with 20 tone-alone trials. When retrained with the sub-conditioning procedure, they displayed again tone-evoked freezing, except when the initial tone was unpaired or a new tone was paired with the 0.1-mA shock, demonstrating fear return rather than fear learning potentiation. We also found that HPC and mPFC tetanic stimulations, applied 24h after the sub-conditioning procedure, similarly reduced this fear return. However, mPFC inactivation abolished temporary HPC tetanus effect, whereas HPC inactivation did not interfere with mPFC tetanus effect. These data confirm our previous findings and reveal the nature of HPC-mPFC interactions in post-extinction modulation of conditioned fear.     

Social brain development and the affective consequences of ostracism in adolescence

Recent structural and functional imaging studies have provided evidence for continued development of brain regions involved in social cognition during adolescence. In this paper, we review this rapidly expanding area of neuroscience and describe models of neurocognitive development that have emerged recently. One implication of these models is that neural development underlies commonly observed adolescent phenomena such as susceptibility to peer influence and sensitivity to peer rejection. Experimental behavioural evidence of rejection sensitivity in adolescence is currently sparse. Here, we describe a study that directly compared the affective consequences of an experimental ostracism manipulation (Cyberball) in female adolescents and adults. The ostracism condition led to significantly greater affective consequences in the adolescents compared with adults. This suggests that the ability to regulate distress resulting from ostracism continues to develop between adolescence and adulthood. The results are discussed in the context of models of neurocognitive development.     

The effect of attending to motor overflow on its voluntary inhibition in young and older adults

Motor overflow refers to involuntary movement or muscle activity coinciding with voluntary movement. We examined whether 16 young adults (18-30 years) and 16 older adults (50-80 years) could voluntarily inhibit overflow. Participants performed a finger pressing task, exerting 50% of their maximal force. Overflow was concurrently recorded in the non-task hand. In the first condition, participants were not made aware of their motor overflow. Then participants, though informed of it, were asked to ignore their overflow. Finally, participants were requested to inhibit overflow with, and then without visual feedback, or vice versa. Overflow was exacerbated when older adults were unaware of it, and was reduced once they were informed. For young adults there was no significant difference between these conditions. Both Age Groups could significantly reduce overflow when so requested, independent of visual feedback. Thus motor overflow can be modulated by higher order cognitive control with directed attention.