Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

Abstract There is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) effective in improving behavioural performance several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In present study, electroencephalogram (EEG) was used to investigate dynamics cortical activity modulated by offline hf-tRNS on a motion direction discrimination task. We EEG measure amplitude motion-related VEPs over parieto-occipital cortex, as well oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis also performed shift event-related perturbation (ERSP) response stimuli between pre- post-stimulation period. The results showed accuracy task not hf-tRNS. Although able elicit motion-dependent VEP components (P1, N2, P2), none them any significant change post-stimulation. found time-dependent increase PSD alpha beta bands regardless protocol. Finally, modulation ERSP condition for gamma when compared pre-stimulation periods Sham stimulation. Overall, these show may induce moderate aftereffects brain activity.