Fig. 3.

Cortical spectral power changes during movement. Application of grip force with the hand contralateral to the recording hemisphere was associated with a suppression of oscillatory power in the low-beta (A; 12–24 Hz) and high-beta range (B; 25–40 Hz) and an increase in power in the broadband gamma range (C; 75–200 Hz). A similar pattern was observed in frontal, precentral, postcentral, and parietal recording sites. Application of grip force with the hand ipsilateral to the recording hemisphere also resulted in beta power suppression; however, it did not elicit a broadband gamma response. Red asterisks denote time points at which activation weights (AW) during contralateral grips are significantly different from zero (different from ITI baseline). Blue asterisks denote time points at which AWs during ipsilateral grips are significantly different from zero. Black asterisks denote time points at which AWs during contralateral grips are significantly different from ipsilateral grips (sign test, Bonferroni corrected for multiple comparisons, P < 0.05).