顶叶在特征捆绑中的作用--对一例典型双侧顶叶损伤病人的研究

本实验以一例典型双侧顶叶损伤患者为研究对象,以数字和几何形状为材料,采用形状和颜色特征识别任务,主要考察了顶叶及空间信息是否影响视觉特征捆绑。结果显示,患者在特征捆绑任务上操作成绩较差,错觉性结合错误远远多于特征错误,且正确反应及错觉性结合受刺激间的距离及呈现方式的影响,表现出距离和位置效应。这些结果表明,顶叶在视觉特征捆绑中起重要作用,这种影响作用很可能与空间注意有关。本研究进一步为特征整合理论提供了神经心理学的证据。     

Stroop效应及其脑机制研究概述

该文回顾了近几十年来有关stroop效应脑机制研究的主要成果与存在的问题,并对未来研究进行了简要展望。     

前额叶皮层在学习记忆中的作用

为了探讨前额叶皮层的功能,在被试进行联合搜索作业(Conjunction search task)时,使用跨颅磁刺激干扰被试者右侧前额叶皮层的活动,观察被试者在学习前后的反应时间的变化。观察到磁刺激干扰前额叶的活动,明显地延长了被试者在学习前的反应时间,对学习之后的反应时间几乎没有变化。这说明右侧前额叶参与了记忆的编码,对记忆的提取没有作用。     

Cognition in schizophrenia: does working memory work?

Recent research suggests that disturbances in social and occupational functioning in individuals with schizophrenia may be more influenced by the severity of cognitive deficits than by the severity of symptoms such as hallucinations and delusions. In this article, I review evidence that one component of cognitive dysfunction in schizophrenia is a deficit in working memory, associated with disturbances in the dopamine system in dorsolateral prefrontal cortex. I suggest that although the cognitive deficits in schizophrenia include working memory dysfunction, because they arise from a disturbance in executive control processes (e.g., the representation and maintenance of context), they extend to a range of cognitive domains. Finally, I discuss the need for further research on the ways in which contextual processing deficits may influence other aspects of this illness, including emotional processing.     

Neuronal symphonies: Musical improvisation and the centrencephalic space of functional integration

Musical improvisation is a sophisticated activity in which a performer realizes, real-time, melodic, and rhythmic sequences in harmony with those from other musicians. The study of musical improvisation helps one to understand not only the cognition of creativity, but also the complex neuronal basis of executive functions, the relation between conscious and unconscious action, and even more. So far, the prevailing models, founded on the brain imaging method, have focused on the connection between the cortical areas and their cognitive processes. Little attention, on the other hand, has been given to the huge variety of subcortical activities, especially in the basal ganglia. This fundamental subcortical component, through its implicit procedures and the role it plays in memory, is responsible to produce new information all the time, allowing the prefrontal cortex to transform a huge and disordered amount of data in explicit creative acts. The basal ganglia are strongly related to the activation of chemical signals generated by dissonance or lack of symmetry between perception and expectation, participating even in the responses to environmental demands according to the circumstances. Thus, they interact with the frontal cortex and with the limbic system, playing a key role in planning and selecting appropriate actions and in decision making. In this text, we try to explain in which sense improvisation is connected to the processes of executive functions, to creativity and to the integrated activity of cortical–subcortical areas controlling the free flow of ideas and to expressive spontaneity. Eventually, we purpose a model according to which structure (improvisational field) and process (improvisational time) take part at the centrencephalic space of functional integration, which, through both competing and cooperating dynamics, gives way to spontaneous composition.     

Predictions penetrate perception: Converging insights from brain,behaviour and disorder

It is argued that during ongoing visual perception, the brain is generating top-down predictions to facilitate, guide and constrain the processing of incoming sensory input. Here we demonstrate that these predictions are drawn from a diverse range of cognitive processes, in order to generate the richest and most informative prediction signals. This is consistent with a central role for cognitive penetrability in visual perception. We review behavioural and mechanistic evidence that indicate a wide spectrum of domains—including object recognition, contextual associations, cognitive biases and affective state—that can directly influence visual perception. We combine these insights from the healthy brain with novel observations from neuropsychiatric disorders involving visual hallucinations, which highlight the consequences of imbalance between top-down signals and incoming sensory information. Together, these lines of evidence converge to indicate that predictive penetration, be it cognitive, social or emotional, should be considered a fundamental framework that supports visual perception.     

内生意图性抑制:自我控制研究的新视角

行为抑制的"停止信号"多来自内生意图行为"是否做"决策过程最后时刻内生性否定指示(即内生意图性抑制),而非环境提前设定。因无法用行为指标(错误率、反应时)评估,需将"自由选择"范式结合f MRI、EEG等技术测量与之相关的脑神经、自主神经生理特点;此外,范式中加入的刺激阈下启动、情绪信息影响了内生意图性抑制的加工过程。未来从三个方面拓展研究:(1)明确背内侧额叶皮质的心理机制;(2)探索人格特质的影响;(3)"停止信号"内生日常化。     

Laboratory of functional neuroelectrical imaging and brain–computer interfacing at Fondazione Santa Lucia

The laboratory of functional neuroelectrical imaging and brain–computer interfacing at Fondazione Santa Lucia is based on the joint work of researchers with a bioengineering and clinical neurophysiology background. The activity is mainly devoted to two aims: the non-invasive investigation of the motor cortical function under physiological and pathological conditions, through the development of advanced processing methods of the electroencephalographic signals; the development of a real-time EEG-based brain–computer interface (BCI) and the study of its use as an aid to enhance (or even to allow) the functional independence of persons with different degrees of motor disability.     

脑可塑性研究综述

本文简要总结了脑可塑性实验研究的三个方面：(1)脑损伤的研究,(2)学习和训练的脑可塑研究,(3)双语习得的研究。目前研究脑可塑的一个重要方向是通过学习和训练,考察认知成分的获得与大脑皮层活动状态变化之间的关系。这些研究说明大脑的成熟是一个动态发展的过程,它的结构和功能在一定程度上具有可塑性。