PLoS ONE · 2011 · 80 citations · 36 references
Life SciencesAudiologyNeuroscienceCognitive NeuroscienceHearing ScienceSensory NeuroscienceAuditory NeurobiologyAuditory NeurophysiologyAuditory NeuroscienceAuditory PhysiologyAuditory ProcessingTemporal HearingAuditory Cortex ProcessingCentral Auditory Processing ChangesInteraction Effect AnalysisPolarity EffectsPrimary Auditory CortexStimulus Polarity EffectsTemporal Auditory ProcessingTranscranial Electrical Stimulation
Polarity‑dependent effects of transcranial direct current stimulation (tDCS) on neuronal processing and pitch perception motivate investigation of its impact on temporal aspects of auditory processing. The study aimed to determine whether tDCS could modulate temporal aspects of auditory processing in healthy adults by altering baseline auditory‑cortex activity. Eleven healthy participants received 2 mA bilateral anodal, cathodal, and sham tDCS over the auditory cortex in a randomized, counterbalanced design, and their temporal resolution was assessed with the Random Gap Detection Test before and during stimulation. Polarity‑dependent tDCS produced significant changes in temporal resolution: anodal stimulation improved Random Gap Detection Test performance by up to 22.5 % (and 29.4 % for clicks), whereas cathodal stimulation impaired performance by 54.5 %, demonstrating that tDCS can positively or negatively modulate auditory temporal processing.
Given the polarity dependent effects of transcranial direct current stimulation (tDCS) in facilitating or inhibiting neuronal processing, and tDCS effects on pitch perception, we tested the effects of tDCS on temporal aspects of auditory processing. We aimed to change baseline activity of the auditory cortex using tDCS as to modulate temporal aspects of auditory processing in healthy subjects without hearing impairment. Eleven subjects received 2mA bilateral anodal, cathodal and sham tDCS over auditory cortex in a randomized and counterbalanced order. Subjects were evaluated by the Random Gap Detection Test (RGDT), a test measuring temporal processing abilities in the auditory domain, before and during the stimulation. Statistical analysis revealed a significant interaction effect of time vs. tDCS condition for 4000 Hz and for clicks. Post-hoc tests showed significant differences according to stimulation polarity on RGDT performance: anodal improved 22.5% and cathodal decreased 54.5% subjects' performance, as compared to baseline. For clicks, anodal also increased performance in 29.4% when compared to baseline. tDCS presented polarity-dependent effects on the activity of the auditory cortex, which results in a positive or negative impact in a temporal resolution task performance. These results encourage further studies exploring tDCS in central auditory processing disorders.
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