title: Excitability changes induced in the human auditory cortex by transcranial direct current stimulation: direct electrophysiological evidence.
abstract: Transcranial direct current stimulation (tDCS) can systematically modify behavior by inducing changes in the underlying brain function. Objective electrophysiological evidence for tDCS-induced excitability changes has been demonstrated for the visual and somatosensory cortex, while evidence for excitability changes in the auditory cortex is lacking. In the present study, we applied tDCS over the left temporal as well as the left temporo-parietal cortex and investigated tDCS-induced effects on auditory evoked potentials after anodal, cathodal, and sham stimulation. Results show that anodal and cathodal tDCS can modify auditory cortex reactivity. Moreover, auditory evoked potentials were differentially modulated as a function of site of stimulation. While anodal tDCS over the temporal cortex increased auditory P50 amplitudes, cathodal tDCS over the temporo-parietal cortex induced larger N1 amplitudes. The results directly demonstrate excitability changes in the auditory cortex induced by active tDCS over the temporal and temporo-parietal cortex and might contribute to the understanding of mechanisms involved in the successful treatment of auditory disorders like tinnitus via tDCS.
authors.affiliation: Department of Neurology, Otto v. Guericke University, Magdeburg, Germany. Tino.zaehle@ovgu.de
authors.forename: Tino
authors.initials: T
authors.lastname: Zaehle
authors.forename: Manuela
authors.initials: M
authors.lastname: Beretta
authors.forename: Lutz
authors.initials: L
authors.lastname: Jäncke
authors.forename: Christoph S
authors.initials: CS
authors.lastname: Herrmann
authors.forename: Pascale
authors.initials: P
authors.lastname: Sandmann
mesh_terms: D000328:Adult; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods*; D004566:Electrodes / Q000592:standards; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology; D012535:Scalp / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D055815:Young Adult