Imagined paralysis reduces motor cortex excitability. (8th April 2022)

• Record Type: Journal Article
• Authors: Hartmann, Matthias; Falconer, Caroline J.; Kaelin‐Lang, Alain; Müri, René M.; Mast, Fred W.
• Is Part Of: Psychophysiology. Volume 59:Number 10(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-08
• Subjects: cortical excitability -- mental imagery -- MEP amplitude -- motor evoked potential (MEP) -- paralysis -- TMS; Psychophysiology -- Periodicals; 612.8
• DOI: 10.1111/psyp.14069
• Languages: English
• ISSNs: 0048-5772

Abstract

Abstract: Mental imagery is a powerful capability that engages similar neurophysiological processes that underlie real sensory and motor experiences. Previous studies show that motor cortical excitability can increase during mental imagery of actions. In this study, we focused on possible inhibitory effects of mental imagery on motor functions. We assessed whether imagined arm paralysis modulates motor cortical excitability in healthy participants, as measured by motor evoked potentials (MEPs) of the hand induced by near‐threshold transcranial magnetic stimulation (TMS) over the primary motor cortex hand area. We found lower MEP amplitudes during imagined arm paralysis when compared to imagined leg paralysis or baseline stimulation without paralysis imagery. These results show that purely imagined bodily constraints can selectively inhibit basic motor corticospinal functions. The results are discussed in the context of motoric embodiment/disembodiment. Abstract : In this study we investigated whether imagining a specific motor impairment has a physiological effect on motor corticospinal function in healthy participants. We found that imagined hand (but not leg) paralysis reduced TMS induced MEPs of the hand muscle. While previous research mainly focused on excitatory effects of mental imagery, our results point to possible inhibitory effects on motor functions. The results may have relevance in the context of (dis)embodiment research and physiological rehabilitation.