FRONTAL LOBE AND CEREBRAL CONTROL OF ADAPTIVE SPATIAL/MOTOR BEHAVIOR

自适应空间/运动行为的额叶和大脑控制

• 批准号: 6162851
• 负责人: Donald J. Crammond
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6162851
• 关键词: Primates; body movement; cerebral cortex; environmental adaptation; frontal lobe /cortex; learning; memory; motor cortex; neural information processing; neuroregulation; sensorimotor system; space perception; visual perception

The goal of this project is to elucidate the neural mechanisms that underlie cognitive information processing during the planning stages of spatial-motor behavior. Neurophysiological recordings of single neuronal activity were undertaken as monkeys performed multidirectional, sequenced reaching movements pre-instructed by visual signals. This design isolated neuronal activity related to movement planning from that related to movement execution. Three major subdivisions of the primate frontal lobe were studied in order to understand the functional role and specialization of each: The primary motor cortex (M1), dorsal premotor cortex (PMd) and supplementary motor area (SMA). In M1 and SMA, the majority of neurons discharged in relation to movement execution. The spatially tuned activity of these neurons conveys information as to movement kinematics such as movement direction and amplitude or to spatial attributes of the target location and movement end-point. In PMd the majority of neurons discharge during movement planning in response to the visual signals which instruct the impending movement. This represents the encoding and storage in working memory of information required to execute movements to remembered spatial targets. PMd neuronal activity was examined in relation to the memorization of instructions signaling a two-stage reaching movement and the proper sequence of its execution. In 25% of PMd neurons this activity was found to encode spatial attributes of remembered reaching movements independent of whether the first or second movement segment was instructed. These cells appear to reliably encode the spatial aspects of every movement segment into a specific part of space. In contrast, in 75% of PMd cells, neuronal responses preferentially encode the remembered instructional information related to one segment of a sequenced reaching movement, usually the first. For a random movement sequence, spatially tuned responses of PMd neurons differ if a constant visual signal instructs planning of the first or second movement segment. Thus, PMd cell activity encodes spatial attributes of impending movements into space and incorporates information as to the correct sequence of movements. For movement sequences instructed by visual signals described by a fixed spatial rule, e.g., targets opposite each other, spatially tuned PMd activity was generally enhanced in response to the first and suppressed in response to the second visual instruction. Since the same visual signals were used to instruct trials with either fixed or random spatial rules, the differential neuronal responses recorded in PMd are attributable to the spatial rule in effect. Thus, PMd neurons are involved in the preparation of reaching movements into space, emit a signal that encodes spatial attributes of either movement kinematics or target endpoints, signal the order of an intended movement sequence, and finally, discharge differentially during the preparation of movement sequences predicted by a fixed spatial rule.

该项目的目标是阐明神经机制 是规划阶段认知信息处理的基础 空间运动行为。单个神经元的神经生理学记录 当猴子进行多向活动时， 由视觉信号预先指示的有序到达动作。这 从中设计与运动计划相关的孤立神经元活动 与动作执行有关。灵长类动物的三个主要分支 对额叶进行了研究，以了解其功能作用和 每个的专业化：初级运动皮层（M1）、背侧前运动皮层 皮层 (PMd) 和辅助运动区 (SMA)。 在 M1 和 SMA 中，大多数神经元的放电量与 运动执行。这些神经元的空间调节活动 传达有关运动运动学的信息，例如运动方向 和幅度或目标位置的空间属性和 运动终点。在 PMd 中，大多数神经元在 响应指示视觉信号的运动计划 即将发生的运动。 这代表了工作中的编码和存储 记忆执行动作所需的信息 空间目标。检查 PMd 神经元活动与 记忆指示两阶段到达运动的指令以及 其执行的正确顺序。在 25% 的 PMd 神经元中， 发现活动对记忆到达的空间属性进行编码 运动与第一运动段还是第二运动段无关 被指示。这些细胞似乎能够可靠地编码空间 每个运动的各个方面都分割成空间的特定部分。在 相比之下，在 75% 的 PMd 细胞中，神经元反应优先编码 记忆的与某一片段相关的教学信息 顺序到达运动，通常是第一个。对于随机运动 如果常数 视觉信号指示第一或第二个动作的计划 部分。因此，PMd 细胞活动编码即将到来的空间属性 进入太空并结合正确的信息 动作顺序。 对于由固定描述的视觉信号指示的运动序列 空间规则，例如目标彼此相对，空间调谐 PMd 活动通常会因响应第一个而增强并受到抑制 响应第二个视觉指令。因为同样的视觉 信号用于指导固定或随机空间的试验 规则，PMd 中记录的差异神经元反应是 归因于有效的空间规则。因此，PMd 神经元是 参与准备进入太空的动作，发出 编码运动运动学或空间属性的信号 目标端点，发出预期运动序列的顺序的信号，以及 最后，在准备运动时进行差异放电 由固定空间规则预测的序列。