Fig. 1

Schematic representation of the study procedure. Prior to each session, MEPs were assessed to establish baseline values and determine the motor spot. Participants were then randomly assigned to one of three stimulation conditions: γ-tACS, β-tACS, or sham-tACS, applied over the primary motor cortex (M1). Following each stimulation session, electrophysiological measures were reassessed. The entire process was repeated after a washout period of at least one week to minimize carryover effects. MEPs: motor evoked potentials. tACS: transcranial alternating current stimulation; blue: β-tACS over the left M1, green: γ-tACS over the left M1, orange: sham