Cortical Processing of visual information during alert and non-alert brain state

描述(申请人提供)：这项建议旨在了解当受试者在警觉和非警醒状态之间转换时，视觉处理的变化。由于控制眼睛位置的行为方法的发展，在理解警觉、专注的受试者视觉感知的中枢机制方面取得了很大的进展。然而，人们对警觉性减弱时起作用的皮质过程知之甚少。清醒、非清醒状态并不等同于麻醉或睡眠状态。在非警觉状态下，我们能够感知，但我们的感知能力不同。人们普遍认为，当我们不警觉时，就会发生事故，但早期丘脑或视觉皮质机制可能在多大程度上对此负责(与高级认知过程相反)是一个悬而未决的问题。这一提议依赖于一种非常适合解决这个问题的独特模型系统：清醒的兔子，一种动物，它的“内部精神生活”透明地在警觉和非警觉状态之间转换，它稳定的眼睛和胆小的天性使它成为这些实验的理想对象。这项拟议的研究将研究清醒受试者大脑状态的变化如何影响视觉丘脑皮质和皮质内网络中发生的信息处理的多个顺序阶段。这些实验将测量大脑皮层输入层和输出层兴奋性和抑制性神经元视觉反应特性的状态依赖变化，并将调查 导致这些变化的潜在机制，在亚阈值和尖峰水平。这项工作将有助于更好地理解动态清醒大脑中视觉处理的皮质机制。从健康的角度来看，这些研究将对我们理解警觉/警觉缺陷如何影响视觉感知和表现产生重要影响，并将为未来人类心理健康和行为障碍的临床研究提供基础。 公共卫生相关性：目前的工作将对我们理解警觉/警觉缺陷如何影响视觉感知和表现产生重要影响。丘脑皮质系统内反应增强的中断与精神疾病有关，这些疾病涉及感觉处理和警觉水平的变化。这一建议将揭示视觉丘脑皮质系统内调节反应增益的机制，并通过这样做，将为未来人类心理健康和行为障碍的临床研究提供基础。

DESCRIPTION (provided by applicant): This proposal aims to understand the changes in visual processing that occur when subjects shift between alert and non-alert waking states. Thanks to the development of behavioral methods for the control of eye position, great advances have been made in understanding central mechanisms of visual perception of alert, attentive subjects. However, there is little understanding of cortical processes that come into play when alertness wanes. The awake, non-alert state is not equivalent to anesthesia, or to sleep states. When non-alert, we are capable of perception, but our perceptual capacities differ. It is commonly believed that "accidents happen" when we are not alert, but the extent to which early thalamic or visual cortical mechanisms may be responsible for this (as opposed to higher cognitive processes) is an open question. This proposal relies on a unique model system that is very well-suited to address this question: the awake rabbit, an animal whose "inner mental life" transparently shifts between alert and non- alert states, and whose stable eyes and diffident nature make it an ideal subject for these experiments. The proposed research will examine how changes in the brain state of awake subjects influence the multiple, sequential stages of information processing that occur within the visual thalamocortical and intracortical network. The experiments will measure state- dependent changes in the visual response properties of excitatory and inhibitory neurons at the input and output layers of the cortex and will investigate the underlying mechanisms leading to these changes, at the subthreshold and spiking level. This work will lead to a better understanding of cortical mechanisms of visual processing in a dynamic, awake brain. From a health perspective, these studies will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance, and will provide the basis for future clinical studies of human mental health and behavioral disorders. PUBLIC HEALTH RELEVANCE: The current work will have an important impact on our understanding of how alertness/vigilance deficits can impact visual perception and performance. A disruption in response gain within thalamocortical systems has been associated with mental diseases that involve changes in sensory processing and the level of vigilance. This proposal will reveal the mechanisms that modulate response gain within the visual thalamocortical system and, by doing so, it will provide the basis for future clinical studies of human mental health and behavioral disorders.