Neurophysiological and behavioural effects of conventional and high definition tDCS

Abstract High-definition transcranial direct current stimulation (HD-tDCS) seems to overcome a drawback of traditional bipolar tDCS: the wide-spread diffusion electric field. Nevertheless, most differences that characterise two techniques are based on mathematical simulations and not real, behavioural neurophysiological, data. The study aims compare widespread tDCS montage (i.e., Conventional with extracephalic return electrode) HD-tDCS, investigating both at level, in terms dexterity performance, neurophysiological as modifications alpha beta power measured EEG. Thirty participants took part three sessions, one for each montage: tDCS, sham. In all conditions, anode was placed over C4, while cathode/s according montage. At baseline, during, after condition, assessed Finger Tapping Task. addition, resting-state EEG recorded baseline stimulation. Power spectrum density calculated, selecting frequency bands: (8–12 Hz) (18–22 Hz). Linear mixed effect models (LMMs) were used analyse modulation induced by tDCS. To evaluate among montages consider state-dependency phenomenon, post-stimulation measurements covariate-adjusted levels. We observed HD-tDCS an reduction lower baseline. Conversely, higher Furthermore, data showed trend towards showing faster response times. distinctively modulated cortical activity. highlights importance considering determine effects individuals.