Transcranial Static Magnetic Field Stimulation Over the Temporal Cortex Modulating the Right Ear Advantage in Dichotic Listening.

OBJECTIVE: Transcranial static magnetic field stimulation (tSMS) has proposed a new, promising, and simple non-invasive brain stimulation method. While several studies gained certain evidence about tSMS effects in the motor, somatosensory, and visual domains, there is still a controversial debate about its general effectiveness. In the present study, we investigated potential tSMS effects on auditory speech processing as measured by a dichotic listening (DL) task. MATERIALS AND METHODS: Fifteen healthy participants received in randomized order on three different days one session of either sham, tSMS over the left, or tSMS over the right auditory cortex (AC). Under stimulation, participants performed a standard DL task with consonant-vowel syllables. Simultaneously, we recorded electroencephalogram from central sites (Fz, Cz, Pz). RESULTS: TSMS over the left AC changed the behavioral performance and modulated auditory evoked potentials. Stimulation of the left AC significantly reduced the right ear advantage during the DL task and the N1 component of auditory evoked potentials in response to these syllables. CONCLUSIONS: The preliminary results of the present exploratory study demonstrate the ability of tSMS to modulate human brain activity on a behavioral as well as physiologic level. Furthermore, tSMS effects on acoustic processing may have clinical implications by fostering potential approaches for a treatment of speech-related pathologies associated with hyperexcitability in the AC.