On the relevance of EEG resting theta activity for the neurophysiological dynamics underlying motor inhibitory control

Abstract

The modulation of theta frequency activity plays a major role in inhibitory control processes. However, the relevance of resting theta band activity and of the ability to spontaneously modulate this resting theta activity for neural mechanisms underlying inhibitory control is elusive. Various theoretical conceptions suggest to take these aspects into consideration. In the current study, we examine whether the strength of resting theta band activity or the ability to modulate the resting state theta activity affects response inhibition. We combined EEG-time frequency decomposition and beamforming in a conflict-modulated Go/Nogo task. A sample of N = 66 healthy subjects was investigated. We show that the strength of resting state theta activity modulates the effects of conflicts during motor inhibitory control. Especially when resting theta activity was low, conflicts strongly affected response inhibition performance and total theta band activity during Nogo trials. These effects were associated with theta-related activity differences in the superior (BA7) and inferior parietal cortex (BA40). The results were very specific for total theta band activity since evoked theta activity and measures of intertrial phase coherency (phase-locking factor) were not affected. The data suggest that the strength of resting state theta activity modulates processing of a theta-related alarm or surprise signal during inhibitory control. The ability to voluntarily modulate theta band activity did not affect conflict-modulated inhibitory control. These findings have important implications for approaches aiming to optimize human cognitive control.

Keywords: EEG; beamforming; response inhibition; resting state; theta oscillations.

Figure 1

Overview of assessment methods, grouping, and outcome variables of the study

Figure 2

Behavioral and neurophysiological data of the resting theta activity grouping during Nogo trials: (a) false alarm rate in compatible versus incompatible trials for the low resting theta power group (blue) and the high resting theta power group (red). (b–d) Time‐frequency decomposition plots of total theta power (b), evoked theta power (c) and PLF (d) for high_baseline and low_baseline group in compatible and incompatible conditions. Plots are shown for correct rejected responses during Nogo trials at electrode Cz with the corresponding scalp topographies. The x‐axis denotes time in seconds (s) relative to stimulus onset, the y‐axis displays frequency in Hz. Power is indicated by color. The interaction between compatibility and group is shown, additionally. (e) Beamforming analysis revealed significant activation differences of total theta power between Nogo and Go trials (overall sample) in the superior frontal gyrus, the supplementary motor area and the medial frontal gyrus (left). For the low_baseline group, significant activation differences of total theta power between incompatible and compatible Nogo trials were found in the superior parietal cortex (BA7) and the angular gyrus (BA39/40; right) [Color figure can be viewed at http://wileyonlinelibrary.com]

Figure 3

Behavioral and neurophysiological data of the modulation grouping during Nogo trials: (a) false alarm rate in compatible vs. incompatible trials for the low modulation group (blue) and the high modulation group (red). (b–d) time‐frequency decomposition plots of total theta power (b), evoked theta power (c) and PLF (d) for high_modulation and low_modulation group in compatible and incompatible conditions. Plots are shown for correct rejected responses during Nogo trials at electrode Cz with the corresponding topographies. The x‐axis denotes time in seconds (s) relative to stimulus onset, the y‐axis displays frequency in hertz (Hz). Power is indicated by color. The interaction between compatibility and group is shown, additionally [Color figure can be viewed at http://wileyonlinelibrary.com]