Istituto Italiano di Tecnologia, Center for Translational Neurophysiology of Speech and Communication (CTNSC), Ferrara, Italy.
Radboud University, Donders Institute for Brain, Cognition and Behavior, Centre for Cognition (DCC), Nijmegen, The Netherlands.
PLoS Biol. 2020 Oct 20;18(10):e3000898. doi: 10.1371/journal.pbio.3000898. eCollection 2020 Oct.
Movements overtly sample sensory information, making sensory analysis an active-sensing process. In this study, we show that visual information sampling is not just locked to the (overt) movement dynamics but to the internal (covert) dynamics of cortico-motor control. We asked human participants to perform continuous isometric contraction while detecting unrelated and unpredictable near-threshold visual stimuli. The motor output (force) shows zero-lag coherence with brain activity (recorded via electroencephalography) in the beta-band, as previously reported. In contrast, cortical rhythms in the alpha-band systematically forerun the motor output by 200 milliseconds. Importantly, visual detection is facilitated when cortico-motor alpha (not beta) synchronization is enhanced immediately before stimulus onset, namely, at the optimal phase relationship for sensorimotor communication. These findings demonstrate an ongoing coupling between visual sampling and motor control, suggesting the operation of an internal and alpha-cycling visuomotor loop.
运动明显地对感官信息进行抽样，使感官分析成为一个主动感知的过程。在这项研究中，我们表明，视觉信息抽样不仅与（明显的）运动动态有关，而且与皮质运动控制的内部（隐蔽的）动态有关。我们要求人类参与者在检测不相关和不可预测的近阈视觉刺激的同时进行连续等长收缩。正如之前所报道的，运动输出（力）与脑活动（通过脑电图记录）在β波段具有零滞后相干性。相比之下，皮质节律在α波段系统地比运动输出提前 200 毫秒。重要的是，当皮质运动α（而不是β）同步性在刺激开始前立即增强时，视觉检测会得到促进，即在感觉运动通讯的最佳相位关系上。这些发现表明视觉抽样和运动控制之间存在持续的耦合，表明存在一个内部的和α循环的视觉运动回路。
