Zusammenfassung
Background: Transcranial random noise stimulation (tRNS) is an innovative technique of non-invasive electrical stimulation. tRNS over the parietal cortex has improved cognitive function in healthy controls and, applied to the auditory cortex, tRNS has shown beneficial effects on tinnitus. Objective/hypothesis: Here we aimed to investigate the effects of tRNS over the auditory cortex on resting ...
Zusammenfassung
Background: Transcranial random noise stimulation (tRNS) is an innovative technique of non-invasive electrical stimulation. tRNS over the parietal cortex has improved cognitive function in healthy controls and, applied to the auditory cortex, tRNS has shown beneficial effects on tinnitus. Objective/hypothesis: Here we aimed to investigate the effects of tRNS over the auditory cortex on resting state and evoked activity in healthy subjects. Methods: We used EEG to measure tRNS induced changes in resting state activity and in auditory steady state responses (ASSRs). Stimuli were 1000 Hz carrier frequency tones, amplitude modulated at 20 Hz and 40 Hz and applied in randomized order. Fourteen subjects participated in a placebo-controlled randomized design study; each received 20 min of tRNS applied over auditory cortices with 2 mA, with a one week interval between real and sham stimulation. Results: We found a significant increase in the ASSR in response to 40 Hz frequency modulated tone and a non-significant trend toward an increase in mean theta band power and variability of the theta band power for the resting state data. Conclusions: Our finding of tRNS induced increased excitability in the auditory cortex parallels previous findings of tRNS effects on motor cortex excitability and is in line with current concepts of tRNS mechanisms such as increase of stochastic resonance. (C) 2014 Elsevier Inc. All rights reserved.