ATTENTION AND VOLUNTARY ACTION IN PREFRONTAL CORTEX

这一提议涉及大脑如何构建其 视觉空间的表示以及如何使用这种表示 行动规划和控制。 关于这一关系有很多观点 视觉空间意识和自主行动之间的联系 一种观点认为 我们所感知的单一意识只不过是 大量低级感觉运动程序相互作用的总和 物理世界。另一种观点认为， 构建一个"心理工作空间"或通用的表示， 空间独立于任何特定效应器系统， 它将这种表示用于运动规划。 注意力和工作 记忆是这个高级空间的重要组成部分， 表示. 大脑的哪些部分可能参与了 这样的代表？ 一个有希望的候选区域是前额叶46区 皮层 先前的研究表明，46区神经元编码 行为相关的视觉刺激的位置，并保持这些 在工作记忆任务期间，包括记忆- 引导扫视任务。 目前的建议审查了 46区的神经元活动与扫视眼的编程之间的关系 运动和视觉引导的手臂运动。 三个实验将 解决以下问题：1）46区神经元是否能够 提供扫视启动和目标所需的信号 选择？2)46区的空间表现是否稳定， 面对持续的运动活动时表现得很健壮吗3)是否可以将 区域46中的各个神经元支持多于一种类型的规划 的运动？ 总的目标是确定46区是否发挥作用 在特定运动的规划和执行中的具体作用，或 在提供空间的多用途表现方面发挥更广泛的作用， 它可以被几个效应器系统使用， 空间注意力转移。 本建议中涉及的问题对以下方面具有实际重要性： 精神障碍患者缺乏维持 对他们的行为进行适当的控制，以及那些无法 启动或控制帕金森病引起的自主运动， 中风、癫痫或其他形式的神经损伤。 拟议 实验应该提供有关认知和 前额叶皮层的运动功能 这将有助于理解 大脑额叶疾病，比如精神分裂症和 癫痫

This proposal is concerned with how the brain constructs its representation of visual space and how this representation is used in movement planning and control. There are many views on the relationship between visual-spatial awareness and voluntary action. One view is that what we perceive as a unitary awareness is nothing more than the sum total of a multitude of low-level sensory-motor programs interacting with the physical world. Another view is that the brain explicitly constructs a "mental workspace" or general purpose representation of space which is independent of any particular effector system, and that it uses this representation for motor planning. Attention and working memory are important components of this high-level spatial representation. What parts of the brain might be involving in forming such a representation? One promising candidate is area 46 of prefrontal cortex. Previous work has shown that area 46 neurons encode the locations of behaviorally relevant visual stimuli and hold these representations on-line during working memory tasks, including memory- guided saccade tasks. The current proposal examines the relationship between neuronal activity in area 46 and the programming of saccadic eye movements and visually-guided arm movements. Three experiments will address the following questions: 1) Are area 46 neurons capable of providing the signals needed for saccade initiation and target selection? 2) Is the representation of space in area 46 stable and robust in the face of ongoing motor activity? 3) Can the activity of individual neurons in area 46 support the planning of more than one type of movement? The overall goal is to determine whether area 46 plays specific role in the planning and execution of particular movements or a more general role in providing a multi-purpose representation of space that can be used by several effector systems as well as guiding covert shifts of spatial attention. The issues dealt with in this proposal are of practical importance to sufferers of psychiatric disorders who lack the ability to maintain appropriate control over their actions, and also those who are unable to initiate or control voluntary movements due to Parkinson's disease, stroke, epilepsy or other forms of neurological damage. The proposed experiments should provide useful information about the cognitive and motor function of prefrontal cortex. This will aid in the understanding of frontal lobe diseases such as schizophrenia and frontal lobe epilepsy.