Brain regions processing complex acoustic features across different musical genres
Music is a fundamental and highly interesting aspect of humanity. The neural basis of music perception has been studied for the most part with relatively simplified stimuli isolating a given element of music, such as by presenting short sound sequences that form tonality or rhythm, and observing which brain areas exhibit responses to such stimulation. Over the last few years, there has been an emerging trend, enabled by developments in non-invasive neuroimaging technology and data analysis methods, towards utilization of naturalistic stimuli during neuroimaging, including free listening of music. What has been wanting, however, are studies looking at which brain areas are consistently activated by musical features across different musical pieces and genres during free listening conditions.
In their recent study, Alluri et al. (2013) presented healthy volunteers musical pieces of various genres that included both instrumental music and music with lyrics during functional magnetic resonance imaging. Musical features were then extracted by automated algorithms included in the so-called MIR toolbox that the authors have developed previously. These complex acoustic feature time series were then used as regression models to predict voxel-wise brain hemodynamic activity recorded during music listening. Cross-validation was used across musical genres and two different subject populations to map areas that respond consistently to the musical complex acoustic features.
It was shown that brain activity can be predicted by the musical complex acoustic features in the auditory, limbic, and motor regions of the brain, as well as in orbitofrontal regions that have been previously associated with evaluative appraisal and not during free music listening per se. Cross-validation identified a region in right superior temporal gyrus that included planum polare and Heschl’s gyrus as the core structure that processes complex acoustic features across musical genres. These highly exciting findings will help pave way for further neuroimaging studies into the neural basis of music processing under naturalistic free music listening conditions.
Reference: Alluri V, Toiviainen P, Lund TE, Wallentin M, Vuust P, Nandi AK, Ristaniemi T, Brattico E. From Vivaldi to Beatles and back: predicting lateralized brain responses to music. Neuroimage 83 (2013) 627-636. http://dx.doi.org/10.1016/j.neuroimage.2013.06.064