Towards the neuronal correlates of visual awareness

描述（由申请人提供） 摘要：大脑是一个由神经元和突触组成的物理系统，它可以产生似乎是所有物理属性中最小的一种：意识。这种转变是如何发生的，一直困扰着几代临床医生和科学家。神经科学在过去几十年中的进步使得探究负责意识的神经回路成为可能。这个建议集中在意识体验的一个特定方面：视觉意识的神经机制和回路。我们建议使用神经生理学，心理物理学和电刺激相结合的研究视觉意识。我们利用一个难得的机会，检查活动在人类枕叶和颞叶使用神经生理学在高空间和时间分辨率（神经元和毫秒），而受试者报告他们的看法。我们提出了两个实验，其中视觉感知是从视觉输入分离：双眼竞争和运动引起的失明。在这两种情况下，尽管有恒定的视觉输入，感知还是会发生变化。我们研究了腹侧视皮层（从初级视皮层到下颞叶皮层）神经元的反应在何处、何时以及如何随着知觉交替而改变其活动模式。此外，我们问这些神经生理反应是否足以通过电刺激局部回路引起感知。意识处理的障碍可能是毁灭性的，是癫痫、植物性昏迷、精神分裂症和自闭症等看似不同的疾病的核心。在视觉的背景下，进一步理解大脑和心灵之间的联系将为解决意识的其他方面铺平道路，并可能对改变我们思考和解决这些具有挑战性的疾病的方式产生深远的影响。 公共卫生相关性：大脑是一个由神经元和突触组成的物理系统，它可以产生似乎是所有物理属性中最小的一种：意识。理解引起感知、感觉和思想的神经机制可以说是当今最大的科学挑战之一。描述神经元活动和感知之间联系的进展将对我们的社会产生深远的影响，特别是在临床应用中。有多种临床病症涉及意识状态的改变，包括癫痫、自闭症、植物性昏迷和精神分裂症等。受这些疾病折磨的人可以活很多年，但他们的生活质量（以及他们周围的朋友和家人的生活质量）可能会严重受损。这些条件导致社会和学习的挑战，往往影响患者的生活。在这些条件的交叉点上，存在着一个基本的挑战，即表达有意识的思想和感知有意识的感受。在所有这些情况下，意识都可以用行为来定义。然而，什么，何时以及如何大脑活动导致意识体验还不清楚。在这里，我们特别关注视觉意识，因为它更容易操纵视觉输入，我们对底层电路有更多的了解，我们可以相当准确地定量评估感知。我们的研究工作将调查引起视觉感知的神经元，位置，电路，相互作用和动力学的类型。

DESCRIPTION (Provided by the applicant) Abstract: The brain, a physical system composed of neurons and synapses, can give rise to what seems to be the least physical property of all: consciousness. How this transformation takes place has preoccupied generations of clinicians and scientists. Advances in Neuroscience over the last several decades make it possible to enquire into the neural circuits responsible for consciousness. This proposal focuses on one particular aspect of conscious experience: the neuronal mechanisms and circuits that underlie visual awareness. We propose to study visual awareness using a combination of neurophysiology, psychophysics and electrical stimulation. We take advantage of a rare opportunity to examine activity in the human occipital and temporal lobes using neurophysiology at high spatial and temporal resolution (neurons and milliseconds) while subjects report their perceptions. We propose two experiments where visual perception is dissociated from the visual input: binocular rivalry and motion-induced blindness. In both cases, perception changes in spite of a constant visual input. We investigate where, when and how neuronal responses along ventral visual cortex (from primary visual cortex to inferior temporal cortex) change their activity patterns with the perceptual alternations. Furthermore, we ask whether those neurophysiological responses are sufficient to elicit perception by electrically stimulating local circuits. Impairments in conscious processing can be devastating and are at the core of seemingly diverse conditions as epilepsy, vegetative coma, schizophrenia and autism. Furthering our understanding of the link between brains and minds in the context of vision will pave the way for addressing other aspects of consciousness and may have profound implications in changing how we think about and address these challenging disorders. Public Health Relevance: The brain, a physical system composed of neurons and synapses, can give rise to what seems to be the least physical property of all: consciousness. Understanding the neuronal mechanisms that give rise to perceptions, feelings and thoughts is arguably one of the biggest scientific challenges today. Advances towards describing the link between neuronal activity and perception will have a profound impact in our society, particularly in clinical applications. There are multiple clinical conditions that involve altered states of consciousness including epilepsy, autism, vegetative coma and schizophrenia among others. Subjects afflicted by these conditions can live for years, yet their quality of life (and that of their surrounding friends and families) can be severely impaired. These conditions lead to social and learning challenges that often impact the afflicted individuals for life. At the intersection of these conditions resides a fundamental challenge to express conscious thoughts and to perceive conscious feelings. In all these cases, consciousness can be behaviorally defined. However, what, when and how brain activity leads to conscious experience is not understood. Here we specifically focus on visual awareness because it is easier to manipulate the visual input, we understand more about the underlying circuitry and we can quantitatively assess perception rather accurately. Our research efforts will investigate the types of neurons, locations, circuits, interactions and dynamics that give rise to visual perception.