NCS-FO: Neural mechanisms of agency in motor control and sensorimotor learning

伸手拿笔写字或用工具钉钉子是每天都会发生的故意行为。这个项目将通过研究代理感背后的神经机制来促进我们对行为的有意识控制的理解--一种感觉，一个人既想要又想要执行一个特定的动作。科学家们现在能够通过电刺激肌肉来提高这种常规动作的表现。对于一些人来说，这种外部刺激的行为被认为是他们自己故意控制的结果；对另一些人来说，这种行为感觉是外部产生的，而不是他们自己的作用。通过测量这两种感觉是有意的刺激动作和感觉是外部控制的动作的神经信号的分布和时间，这项研究将测试认知和神经意识理论，以及行为启动和控制的主观经验。这些发现可以引导人们以新的方式思考行动的神经科学。它们还可以为改善机器人控制的用户系统界面提供指导，并为人类技术前沿的未来工作提供培训方法，为疾病或创伤后运动功能恢复开发新的假肢和新的康复疗法。本项目由神经和认知系统综合策略(NCS)资助，NCS是由计算机和信息科学与工程(CEISE)、教育和人力资源(EHR)、工程(ENG)和社会、行为和经济科学(SBE)等部门联合支持的多学科项目。该研究将通过功能性电刺激(FES)、机器人外骨骼的使用或虚幻运动的诱导来增强通常可控制的人类运动，以探索必然的放电和再传入信号在决定代理感的时间进程和强度中的作用。一组六个实验将确定代理在运动学习中的作用，代理丢失的条件，以及在多大程度上可以在不失去代理感觉的情况下对自愿动作进行外部修改。将使用人类脑电(EEG)和功能磁共振成像(FMRI)测量运动系统和躯体感觉皮质中的活动和时间，以模拟神经反应。当感觉到增强的运动是自发的时，所进行的测量将与当运动被体验为外部引导时所进行的测量进行比较。增强运动中的有意作用感和被动无意运动之间的这种对比将与不同形式的外部运动增强的神经活动模式有关。动作的外部刺激的代理感预示着运动学习的改善，与代理相关的神经信号将被用来模拟运动学习。这些分析将被用来测试与传出运动线索、纹状体奖励系统和学习相关的有意行为中的代理和意识的特定模型。了解有意识地控制行为的神经机制可以为神经工程学和大脑启发的设计带来新的模型，提供关于行为和学习认知控制的个体差异和变异的新信息，并对神经过程如何在现实和复杂的环境中运行产生新的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Reaching for a pen to write or a tool to hammer a nail are the kinds of intentional actions produced every day. This project will advance our understanding the conscious control of behavior by investigating the neural mechanisms that underlie the sense of agency – the feeling that one has both intended to and executed a particular movement. Scientists are now able to stimulate muscles electrically in order to enhance the performance of such routine movements. For some people, this externally stimulated action is felt to be the result of their own intentional control; for others, the action feels externally produced and not of their own agency. By measuring the distribution and timing of neural signals in these two situations of stimulated action that is felt to be intentional compared to movements that are felt to be externally controlled, the research will test cognitive and neural theories of consciousness and subjective experience in the initiation and control of behavior. The findings can lead to new ways of thinking about the neuroscience of action. They can also provide guidance for the improvement of user-system interfaces for robotic control and training methods for the future of work at the human-technology frontier, the development of new prosthetics as well as new rehabilitation therapies for the recovery of motor function following disease or trauma. This project is funded by Integrative Strategies for Understanding Neural and Cognitive Systems (NCS), a multidisciplinary program jointly supported by the Directorates for Computer and Information Science and Engineering (CISE), Education and Human Resources (EHR), Engineering (ENG), and Social, Behavioral, and Economic Sciences (SBE).The research will enhance typically controlled human motor movements by manipulating them externally through functional electrical stimulation (FES), the use of a robotic exoskeleton, or the induction of illusory motion in order to probe the role of corollary discharge and reafferent signals in determining the time course and strength of the sense of agency. A set of six experiments will identify the role of agency in motor learning, the conditions under which agency is lost, and the extent to which voluntary movements can be externally modified without losing the sense of agency. Measurements of the activity and timing in the motor system and in somatosensory cortex using human electroencephalography (EEG) and functional Magnetic Resonance Imaging (fMRI) will be used to model neural responses. Measurements taken when enhanced movement is felt to be self-initiated will be compared to those taken when the movement is experienced as externally guided. This contrast between a sense of intentional agency in enhanced movement and passive unintentional movement will be related to the patterns of neural activity across different forms of external movement enhancement. The sense of agency for external stimulation of action has been predictive of improved motor learning and the neural signals related to agency will be used to model motor learning. These analyses will be used to test specific models of agency and consciousness in intentional action relating efferent motor cues, the striatal reward system, and learning. Understanding the neural mechanisms of conscious control of behavior can lead to new models for neuroengineering and brain-inspired design, provide new information about individual differences and variation in cognitive control of behavior and learning, and yield new understanding of how neural processes operate in realistic and complex environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.