Abstract
The auditory cortex is well-known to be critical for music perception, including the perception of consonance and dissonance. Studies on the neural correlates of consonance and dissonance perception have largely employed non-invasive electrophysiological and functional imaging techniques in humans as well as neurophysiological recordings in animals, but the fine-grained spatiotemporal dynamics within the human auditory cortex remain unknown. We recorded electrocorticographic (ECoG) signals directly from the lateral surface of either the left or right temporal lobe of eight patients undergoing neurosurgical treatment as they passively listened to highly consonant and highly dissonant musical chords. We assessed ECoG activity in the high gamma (γhigh, 70–150 Hz) frequency range within the superior temporal gyrus (STG) and observed two types of cortical sites of interest in both hemispheres: one type showed no significant difference in γhigh activity between consonant and dissonant chords, and another type showed increased γhigh responses to dissonant chords between 75 and 200 ms post-stimulus onset. Furthermore, a subset of these sites exhibited additional sensitivity towards different types of dissonant chords, and a positive correlation between changes in γhigh power and the degree of stimulus roughness was observed in both hemispheres. We also observed a distinct spatial organization of cortical sites in the right STG, with dissonant-sensitive sites located anterior to non-sensitive sites. In sum, these findings demonstrate differential processing of consonance and dissonance in bilateral STG with the right hemisphere exhibiting robust and spatially organized sensitivity toward dissonance.
Highlights
Simultaneous pitch combinations form the building blocks of harmony, a fundamental characteristic of Western tonal music
Analysis of significant superior temporal gyrus (STG) sites in both hemispheres revealed two response types: one that showed increased γhigh activity in response to dissonant chords than consonant chords, and one that showed no difference in γhigh activity between chord types
As cortical γhigh power has been shown to correlate with neuronal firing (Ray et al, 2008), our observations are consistent with electrophysiological depth recordings in the auditory cortex of monkeys and humans, where groups of neuronal populations in primary auditory cortex exhibited greater oscillatory phaselocked activity in response to dissonant chords than consonant chords (Fishman et al, 2001)
Summary
Simultaneous pitch combinations form the building blocks of harmony, a fundamental characteristic of Western tonal music These pitch relationships can be described as either consonant (often associated with pleasantness) or dissonant (often associated with unpleasantness). The auditory cortex plays a crucial role in multiple aspects of music perception, from basic pitch and rhythm discriminations to complex cognitive tasks in music performance (Peretz and Zatorre, 2005) Not surprisingly, it is implicated in the perception of consonance and dissonance, as evidenced by lesion studies (Tramo et al, 1990; Peretz et al, 2001; Brattico et al, 2003), non-invasive electrophysiological methods (Tervaniemi et al, 1999; Kuriki et al, 2005; Minati et al, 2009) and functional neuroimaging techniques (Foss et al, 2007; Minati et al, 2009; Daikoku et al, 2012). As consonance and dissonance are perceptual products of pitch combinations, it remains to be seen whether this spatial organization extends to the processing of consonant and dissonant pitch intervals in anterolateral regions of the auditory cortex
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
