Neurocognitive Dynamics Of Sleep Onset

在国家科学基金会的支持下，沃克博士将对人类大脑系统进行为期一年的研究，这些系统控制着从全意识下降到睡眠意识下降的过程，并产生入睡做梦的认知体验。睡眠是人类生活中必不可少的一部分，约占我们时间的三分之一。从清醒到睡眠的转变可以说是人类大脑和思维正常经历的最引人注目的转变。尽管我们开始了解是什么大脑机制触发了这种转变，但产生睡眠状态的实际过程仍然未知。另一种有趣的是伴随着这种清醒-睡眠转换的精神体验，通常包括短暂的幻觉/梦，包括视觉和听觉事件以及运动的感觉。最近的研究表明，这些入睡梦与对新的白天经历的记忆的重演和巩固有关，特别是那些需要学习新技能的记忆(例如，在很长一段时间内从事新的身体或精神活动，如滑雪的第一天)。沃克博士和他的同事通过让受试者在白天长时间玩滑雪模拟器游戏，能够可靠地产生几乎相同的、刻板印象的入睡梦。本项目使用这种方法来观察和控制志愿者在功能磁共振扫描仪中进行大脑成像时入睡做梦的认知过程。识别入睡过程中涉及的大脑机制将为基础神经科学和临床研究提供广泛价值的信息。它不仅会增加我们对睡眠大脑和做梦大脑的神经认知基础的了解，还会扩大我们对人类感觉和感知经验的理解，以及新知识和技能是如何获得、学习和再加工的。这些信息还将为人类感知、认知和学习的新理论提供一个平台，并将有助于制定各种神经和睡眠障碍的新治疗方法。

With National Science Foundation support, Dr. Walker will conduct a year long investigation of the human brain systems which control the descent from full consciousness into the reduced consciousness of sleep and produce the cognitive experience of sleep onset dreaming. Sleep is an essential part of human life, occupying approximately one third of our time. The shift from wake to sleep arguably represents the most striking transition that the human brain and mind normally experiences. Although we are beginning to understand what brain mechanisms trigger this shift, the actual processes that produce the state of sleep remain unknown. Of additional interest is the type of mental experience that accompanies this wake-sleep transition, often involving brief hallucinations/dreams containing visual and auditory events as well as feelings of movement. Recent studies have suggested that these sleep-onset dreams are related to the re-play and consolidation of memories of novel daytime experiences, particularly those requiring the learning of new skills (e.g. engage in novel physical or mental activities for extended periods of time such as the first day of skiing). Dr. Walker and colleagues have been able to reliably produce near identical, stereotyped sleep-onset dreams by having human subjects play a ski simulator game for extended periods during the day. The present project uses this method to observe and control the cognitive processes of sleep onset dreaming as volunteers brains are being imaged in functional magnetic resonance scanner.Identifying the brain mechanisms involved in the sleep-onset process would provide information of wide value to both the basic neurosciences and to clinical research. It would not only increase our understanding of the neurocognitive basis of both the sleeping brain and the dreaming mind, but would also expand our understanding of human sensory and perceptual experience and of how new knowledge and skills are acquired, learned and reprocessed. This information would also provide a platform for new theories of human perception, cognition and learning, and will assist in the formulation of new treatments for a variety of neurological and sleep disorders.