Tomassini Alice, D'Ausilio Alessandro
Center for Translational Neurophysiology for Speech and Communication, Fondazione Istituto Italiano di Tecnologia , Ferrara , Italy.
Department of Robotics, Brain and Cognitive Sciences (RBCS), Fondazione Istituto Italiano di Tecnologia, Genova, Italy.
J Neurophysiol. 2018 Feb 1;119(2):380-388. doi: 10.1152/jn.00496.2017. Epub 2017 Oct 18.
Movement planning and execution rely on the anticipation and online control of the incoming sensory input. Evidence suggests that sensorimotor processes may synchronize visual rhythmic activity in preparation of action performance. Indeed, we recently reported periodic fluctuations of visual contrast sensitivity that are time-locked to the onset of an intended movement of the arm. However, the origin of the observed visual modulations has so far remained unclear because of the endogenous (and thus temporally undetermined) activation of the sensorimotor system that is associated with voluntary movement initiation. In this study, we activated the sensorimotor circuitry involved in the hand control in an exogenous and controlled way by means of peripheral stimulation of the median nerve and characterized the spectrotemporal dynamics of the ensuing visual perception. The stimulation of the median nerve triggers robust and long-lasting (∼1 s) alpha-band oscillations in visual perception, whose strength is temporally modulated in a way that is consistent with the changes in alpha power described at the neurophysiological level after sensorimotor stimulation. These findings provide evidence in support of a causal role of the sensorimotor system in modulating oscillatory activity in visual areas with consequences for visual perception. NEW & NOTEWORTHY This study shows that the peripheral activation of the somatomotor hand system triggers long-lasting alpha periodicity in visual perception. This demonstrates that not only the endogenous sensorimotor processes involved in movement preparation but also the passive stimulation of the sensorimotor system can synchronize visual activity. The present work suggests that oscillation-based mechanisms may subserve core (task independent) sensorimotor integration functions.
运动规划和执行依赖于对传入感觉输入的预测和在线控制。有证据表明,感觉运动过程可能会在准备动作执行时同步视觉节律活动。事实上,我们最近报告了视觉对比敏感度的周期性波动,这些波动与手臂预期运动的开始在时间上锁定。然而,由于与自愿运动启动相关的感觉运动系统的内源性(因此时间上不确定)激活,迄今为止观察到的视觉调制的起源仍不清楚。在这项研究中,我们通过正中神经的外周刺激以外源性和可控的方式激活了参与手部控制的感觉运动回路,并表征了随之而来的视觉感知的频谱时间动态。正中神经的刺激在视觉感知中触发了强烈且持久(约1秒)的α波段振荡,其强度在时间上的调制方式与感觉运动刺激后在神经生理学水平上描述的α功率变化一致。这些发现为感觉运动系统在调节视觉区域的振荡活动以影响视觉感知方面的因果作用提供了证据。新观点与值得注意之处 本研究表明,躯体运动手部系统的外周激活在视觉感知中触发了持久的α周期性。这表明不仅运动准备中涉及的内源性感觉运动过程,而且感觉运动系统的被动刺激都可以同步视觉活动。目前的工作表明,基于振荡的机制可能有助于核心(与任务无关)的感觉运动整合功能。