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Electrocorticographic dissociation of alpha and beta rhythmic activity in the human sensorimotor system

2019; eLife Sciences Publications Ltd; Volume: 8; Linguagem: Inglês

10.7554/elife.48065

2050-084X

Arjen Stolk, Loek Brinkman, Mariska J. Vansteensel, Erik J. Aarnoutse, Frans S.S. Leijten, Chris Dijkerman, Robert T. Knight, Floris P. de Lange, Ivan Toni,

Neuroscience and Neural Engineering

This study uses electrocorticography in humans to assess how alpha- and beta-band rhythms modulate excitability of the sensorimotor cortex during psychophysically-controlled movement imagery. Both rhythms displayed effector-specific modulations, tracked spectral markers of action potentials in the local neuronal population, and showed spatially systematic phase relationships (traveling waves). Yet, alpha- and beta-band rhythms differed in their anatomical and functional properties, were weakly correlated, and traveled along opposite directions across the sensorimotor cortex. Increased alpha-band power in the somatosensory cortex ipsilateral to the selected arm was associated with spatially-unspecific inhibition. Decreased beta-band power over contralateral motor cortex was associated with a focal shift from relative inhibition to excitation. These observations indicate the relevance of both inhibition and disinhibition mechanisms for precise spatiotemporal coordination of movement-related neuronal populations, and illustrate how those mechanisms are implemented through the substantially different neurophysiological properties of sensorimotor alpha- and beta-band rhythms.