Unilateral hf-trns over the temporal cortex does not influence pleasantness of musical chords

The “consonance effect” is the pleasant and unpleasant evaluation attributed to consonant and dissonant music, respectively. Different studies in this domain revealed a left-hemispheric superiority for dissonance and a right-hemispheric superiority for consonance. We investigated the causal relationship between the consonance effect and the activity of the cerebral hemispheres by applying high frequency transcranial Random Noise Stimulation (hf-tRNS)over the left or right auditory cortex in a group of 24 healthy volunteers. Results confirm the consonance effect, dissonant chords being judged as more unpleasant than consonant chords, and show that hf-tRNS does not influence the pleasantness evaluations of chords. We speculate that the auditory cortex is directly involved in consonance and dissonance processing, but that pleasantness evaluations could take place in the anterior areas of the brain. This is the first evidence concerning the effects of the modulatory activity in each cerebral hemisphere and the consonance effect.