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。     

THE EPIC OF PERSONAL DEVELOPMENT AND THE MYSTERY OF SMALL WORKING MEMORY

Abstract. A partial analogy exists between the lifespan neuropsychological development of individuals and the biological evolution of species: In both of these major categories of growth, progressive emergence of wholes transcends inherently limited part‐processes. The remarkably small purview of each moment of consciousness experienced by an individual may be a crucial aspect of maintaining organization in that individual's cognitive development, protecting it from combinatorial chaos. In this essay I summarize experimental psychology research showing that working memory capacity comprises the so‐called magical number 7±2 items, not only for words and digits but for spatial items and other sorts of cognitive materials, and not only in humans but also in other species. This is so to such an extent that 7±2 may be a “constant of nature.” The small quantity range 7±2 independent items, which builds upon a more elementary, instantaneous working memory capacity of three or four items, is surprisingly independent of the time duration of a cognitive task. Moreover, it is largely independent of ontogeny. Explanations of these powerful facts about working memory are offered here within both a functionalistic framework and a framework of hypothetical neural processes. At the neural level, working memory dynamics may comprise certain brain wave harmonics or topological relationships in the sheetlike cortex. Within the functionalistic framework, I suggest an additional analogy, pertaining to cultural evolution, with Tom Gilbert's work on risk analysis and “the global problematic” that follows from unforeseen consequences of the expansiveness of human ambition. Several connections are drawn with ideas presented by participants in the Chicago Religion and Science Group about how theologies and sciences try to understand the possibility of adaptive exercises of human freedom in the face of the extreme finiteness of each human individual.     

计时和计数的相似与差异

计时指判断时距的长短, 计数指辨别刺激呈现数目的多少。研究者发现计时和计数具有相似性, 表现在类似的基本原理, 对时间和数目的记忆都受到时间延迟的影响, 跨通道效应类似, 而且药物对它们的影响一致。模式控制模型认为计时和计数共享同一机制, 量值理论的观点是时间和数目等不同维度具有部分重叠的同一表征形式。计时和计数都激活了前额、顶叶、小脑等区域, 但两者在行为结果和激活的脑区上也有部分差异。计时和计数具有同一表征还是两者独立加工, 只在对比反应阶段存在共同机制仍需要进一步研究。     

Pre‐frontal‐insular‐cerebellar modifications correlate with disgust feeling blunting after subthalamic stimulation: A positron emission tomography study in Parkinson's disease

Subthalamic nucleus (STN) deep brain stimulation (DBS) has recently advanced our understanding of the major role played by this basal ganglion in human emotion. Research indicates that STN DBS can induce modifications in all components of emotion, and neuroimaging studies have shown that the metabolic modifications correlated with these emotional disturbances following surgery are both task‐ and sensory input‐dependent. Nevertheless, to date, these modifications have not been confirmed for all emotional components, notably subjective emotional experience, or feelings. To identify the neural network underlying the modification of feelings following STN DBS, we assessed 16 patients with Parkinson's disease before and after surgery, using both subjective assessments of emotional experience and ¹⁸[F]fluorodeoxyglucose positron emission tomography (¹⁸FDG‐PET). The patients viewed six film excerpts intended to elicit happy, angry, fearful, sad, disgusted, and neutral feelings, and they self‐rated the intensity of these feelings. After DBS, there was a significant reduction in the intensity of the disgust feeling. Correlations were observed between decreased disgust experience and cerebral glucose metabolism (FDG uptake) in the bilateral pre‐frontal cortices (orbitofrontal, dorsolateral, and inferior frontal gyri), bilateral insula, and right cerebellum. We suggest that the STN contributes to the synchronization process underlying the emergence of feelings.     

Contribution of the parafascicular nucleus in the spontaneous object recognition task

The parafascicular (PF) nucleus, a posterior component of the intralaminar nuclei of the thalamus, is considered to be an essential structure in the feedback systems of basal ganglia–thalamo-cortical circuits critically involved in cognitive processes. The specific role played by multimodal information encoded in PF neurons in learning and memory processes is still unclear. We conducted two experiments to investigate the role of the PF in the spontaneous object recognition (SOR) task. The behavioral effects of pretraining rats with bilateral lesions of PF with N-methyl-D-aspartate (NMDA) were compared to vehicle controls. In the first experiment, rats were tested on their ability to remember the association immediately after training trials and in the second experiment after a 24 h delay. Our findings provide evidence that PF lesions critically affect both SOR tests and support its role in that non-spatial form of relational memory.