TY - JOUR T1 - Voluntary inhibition of physiological mirror activity: an EEG-EMG study JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0326-20.2020 SP - ENEURO.0326-20.2020 AU - T Maudrich AU - R Kenville AU - D Maudrich AU - A Villringer AU - P Ragert AU - VV Nikulin Y1 - 2020/10/14 UR - http://www.eneuro.org/content/early/2020/10/14/ENEURO.0326-20.2020.abstract N2 - Physiological mirror activity (pMA), observed in healthy human adults, describes the involuntary co-activation of contralateral homologous muscles during unilateral limb movements. Here we provide novel evidence, using neuromuscular measurements (electromyography), that the amplitude of pMA can be voluntarily inhibited during unilateral isometric contractions of intrinsic hand muscles after informing human participants (10 male, 10 female) about its presence and establishing a basic understanding of pMA mechanisms through a standardized protocol. Importantly, significant suppression of pMA was observed immediately after participants were asked to inhibit it, despite the absence of any online feedback during task execution and without special training. Moreover, we observed that the decrease of pMA was specifically accompanied by an increase in relative frontal delta power recorded with electroencephalography. Correlation analysis further revealed an inverse association between the individual amplitude of pMA and frontal delta power that reached significance once participants started to inhibit. Taken together, these results suggest that delta power in frontal regions might reflect executive processes exerting inhibitory control over unintentional motor output, in this case pMA. Our results provide an initial reference point for the development of therapeutic applications related to the neurorehabilitation of involuntary movements which could be realized through the suppression of pMA observed in the elderly before it would fully manifest in undesirable overt movement patterns.Significance statement Unilateral movements evoke unintended activation of contralateral muscles, especially when such movements are performed with high effort. This motor phenomenon, termed mirror activity, is observed not only in pathological conditions of the CNS but also in healthy individuals, where it is known as physiological mirror activity. Surprisingly, as we show in our study, participants are capable of suppressing this unintended co-activation after being informed of its presence. Suppression was accompanied by increased delta power in frontal areas. This suggests that unintentional motor output can be suppressed via executive processes, i.e. inhibitory control. We offer an initial reference point for therapeutic applications regarding neurorehabilitation of involuntary movements and a possible strategy to counteract the age-related increase in mirror activity. ER -