All talk? Left temporal alpha oscillations are not specific to verbal-analytical processing during conscious motor control

Abstract

The present study tested the validity of inferring verbal-analytic motor processing from EEG left-temporal alpha activity. Participants (n = 20) reached for and transport a jar under three conditions: one control condition and two self-talk conditions aimed at eliciting either task-unrelated verbal processing or task-related conscious control, while 32-channel EEG and kinematics were recorded. Compared to the control condition, both self-talk conditions elicited greater self-reported levels of verbal processing, but only the task-related self-talk condition was accompanied by greater left temporal activity (i.e., EEG alpha power decreased) during movement production. However, this increase was not localised to the left temporal region but was rather evident over all scalp regions examined, suggesting an interpretation more consistent with diminished neural efficiency. No effects for left temporal-frontal (T7-Fz) connectivity were detected across conditions. Our results failed to endorse left-temporal EEG alpha activity as valid index of verbal-analytic processing during motor tasks.