Context-dependent processing in sensorimotor cortex

摘要 人类以无数种方式与环境互动，并可以在各种活动之间无缝切换。连 对于看似简单的任务，各种感觉输入被整合在一起，以创建完成任务的运动计划。 以拿起一个玻璃杯为例。视觉、触觉和本体感觉输入提供有关 对象的位置和重量以及肢体状态。附加的感觉和上下文输入还可以 影响运动。例如，如果一个人打算拿一个杯子，她可能会拿起一个不同的杯子。 喝酒，而不是收拾桌子。如果杯子很满，她可能会更小心地握住，以免洒出来。 电机控制方案的改变。我们的中心假设是任务的感觉和运动方面 环境系统地调节神经对行为的表征以及有意识的感官知觉。 我们将操纵任务情境的各个方面来研究抓取和物体过程中的感觉运动加工 探索任务。来自人类运动皮质的皮质内记录将被用于研究神经 任务目标、运动控制方案以及预期和预期的各种操作的动作表示 实际的感官输入。感觉输入将使用完整的知觉(视觉)和皮质内提供 微刺激躯体感觉皮质以传递皮肤感觉。涉及物体抓取的任务和 探索将通过脑机接口(BCI)和机械臂和手进行，这使得我们能够 精确控制神经活动和运动以及体感输入之间的映射。 以前的研究支持这样一种观点，即在患有高血压的人的尝试运动过程中产生的神经活动 脊髓损伤与运动变量表现出与健全受试者相同的关系。同样， 刺激慢性四肢瘫痪患者的躯体感觉皮质会产生局部感觉 遵循预期的空间组织。 种群水平的分析将应用于神经元记录，以揭示神经活动的模式 由环境的每个方面生成，以更好地了解目标、运动控制方案和 预期和实际的感觉输入会影响动作的神经表征。我们将研究远见和 在物体探索过程中，触觉被整合以驱动有意识的感知。意识知觉 将通过口头报告和心理物理实验来记录。这个项目将解决基本的- 关于语境对感觉运动加工的影响的科学问题。这项研究的发现可能 广泛影响神经康复方法，同时还提高了可推广性和性能 用于恢复上肢功能的BCI。

ABSTRACT Humans interact with their environment in countless ways and can switch seamlessly between activities. Even for seemingly simple tasks, a variety of sensory inputs are integrated to create a motor plan to complete a task. Take the example of picking up a glass. Visual, tactile, and proprioceptive inputs provide cues about the position and weight of the object as well as limb state. Additional sensory and contextual inputs can also influence the movement. For example, a person might pick up a glass differently if she is intending to take a drink, versus clear off a table. She may grasp a glass more carefully if it is very full to avoid spilling it requiring a change in the motor control scheme. Our central hypothesis is that sensory and motor aspects of task context systematically modulate the neural representation of action as well as conscious sensory perception. We will manipulate aspects of task context to study sensorimotor processing during grasping and object exploration tasks. Intracortical recordings from human motor cortex will be used to study the neural representation of action for various manipulations of task goals, motor control schemes, and expected and actual sensory inputs. Sensory input will be provided using both intact perception (vision) and intracortical microstimulation of somatosensory cortex to impart cutaneous sensations. Tasks involving object grasping and exploration will be performed with a brain-computer interface (BCI) and robotic arm and hand, which allows us to precisely control the mapping between neural activity and movement as well as the somatosensory inputs. Previous work supports the idea that neural activity generated during attempted movements in people with spinal cord injury exhibits the same relationship to movement variables as an able-bodied subject. Similarly, stimulation of somatosensory cortex in a person with chronic tetraplegia generates localized sensations that follow the expected spatial organization. Population-level analysis will be applied to the neuronal recordings to reveal patterns of neural activity generated by each facet of context to gain a better understanding of how goals, motor control schemes, and expected and actual sensory inputs influence the neural representation of action. We will study how vision and tactile sensation are integrated to drive conscious perception during object exploration. Conscious perception will be documented via verbal report as well as psychophysical experiments. This project will address basic- science questions about the influence of context on sensorimotor processing. The findings of this study could broadly impact neurorehabilitation approaches, while also improving the generalizability and performance of BCIs for restoring upper limb function.