Department of Psychiatry and Psychotherapy, University of Marburg, Marburg, Germany.
Hum Brain Mapp. 2023 Dec 1;44(17):6198-6213. doi: 10.1002/hbm.26506. Epub 2023 Oct 4.
Self-initiated movements are accompanied by an efference copy, a motor command sent from motor regions to the sensory cortices, containing a prediction of the movement's sensory outcome. Previous studies have proposed pre-motor event-related potentials (ERPs), including the readiness potential (RP) and its lateralized sub-component (LRP), as potential neural markers of action feedback prediction. However, it is not known how specific these neural markers are for voluntary (active) movements as compared to involuntary (passive) movements, which produce much of the same sensory feedback (tactile, proprioceptive) but are not accompanied by an efference copy. The goal of the current study was to investigate how active and passive movements are distinguishable from premotor electroencephalography (EEG), and to examine if this change of neural activity differs when participants engage in tasks that differ in their expectation of sensory outcomes. Participants made active (self-initiated) or passive (finger moved by device) finger movements that led to either visual or auditory stimuli (100 ms delay), or to no immediate contingency effects (control). We investigated the time window before the movement onset by measuring pre-movement ERPs time-locked to the button press. For RP, we observed an interaction between task and movement. This was driven by movement differences in the visual and auditory but not the control conditions. LRP conversely only showed a main effect of movement. We then used multivariate pattern analysis to decode movements (active vs. passive). The results revealed ramping decoding for all tasks from around -800 ms onwards up to an accuracy of approximately 85% at the movement. Importantly, similar to RP, we observed lower decoding accuracies for the control condition than the visual and auditory conditions, but only shortly (from -200 ms) before the button press. We also decoded visual vs. auditory conditions. Here, task is decodable for both active and passive conditions, but the active condition showed increased decoding shortly before the button press. Taken together, our results provide robust evidence that pre-movement EEG activity may represent action-feedback prediction in which information about the subsequent sensory outcome is encoded.
自主运动伴随着传出副本，即从运动区域发送到感觉皮质的运动指令，其中包含对运动感觉结果的预测。先前的研究提出了前运动事件相关电位（ERP），包括准备电位（RP）及其侧化子成分（LRP），作为动作反馈预测的潜在神经标记物。然而，目前尚不清楚这些神经标记物对于自主（主动）运动与非自主（被动）运动有多么具体，因为后者产生了几乎相同的感觉反馈（触觉、本体感觉），但没有传出副本。本研究的目的是探讨主动和被动运动如何从前运动脑电图（EEG）中区分出来，并研究当参与者从事预期感觉结果不同的任务时，这种神经活动的变化是否不同。参与者进行主动（自主发起）或被动（手指由设备移动）手指运动，这些运动导致视觉或听觉刺激（100ms 延迟），或没有即时的关联效应（对照）。我们通过测量与按钮按下时间锁定的运动前 ERP 来研究运动前的时间窗口。对于 RP，我们观察到任务和运动之间的相互作用。这是由视觉和听觉条件下的运动差异驱动的，但在对照条件下则没有。LRP 则仅显示运动的主要影响。然后，我们使用多元模式分析来解码运动（主动与被动）。结果表明，在所有任务中，从大约-800ms 开始，直到运动时达到约 85%的准确性，都存在斜坡解码。重要的是，与 RP 类似，我们观察到对照条件下的解码准确性低于视觉和听觉条件，但仅在按钮按下前短暂（从-200ms 开始）。我们还解码了视觉与听觉条件。在这里，主动和被动条件都可以对任务进行解码，但在按钮按下前，主动条件的解码能力有所提高。总之，我们的结果提供了有力的证据，表明运动前 EEG 活动可能代表动作反馈预测，其中包含对后续感觉结果的信息编码。
