Morphometry of the amusic brain: a two-site study

Abstract

Congenital amusia (or tone deafness) is a lifelong disability that prevents otherwise normal-functioning individuals from developing basic musical skills. Behavioural evidence indicates that congenital amusia is due to a severe deficit in pitch processing, but very little is known about the neural correlates of this condition. The objective of the present study was to investigate the structural neural correlates of congenital amusia. To this aim, voxel-based morphometry was used to detect brain anatomical differences in amusic individuals relative to musically intact controls, by analysing T1-weighted magnetic resonance images from two independent samples of subjects. The results were consistent across samples in highlighting a reduction in white matter concentration in the right inferior frontal gyrus of amusic individuals. This anatomical anomaly was correlated with performance on pitch-based musical tasks. The results are consistent with neuroimaging findings implicating right inferior frontal regions in musical pitch encoding and melodic pitch memory. We conceive the present results as a consequence of an impoverished communication in a right-hemisphere-based network involving the inferior frontal cortex and the right auditory cortex. Moreover, the data point to the integrity of white matter tracts in right frontal brain areas as being key in acquiring normal musical competence.

EPS Prize Lecture: Characterizing congenital amusia

“…Structural neuroimaging data reveal subtle differences in the brains of individuals with congenital amusia, in inferior frontal cortex and superior temporal areas, variously in the left hemisphere (Hyde et al, 2007;Hyde, Zatorre, Griffiths, Lerch, & Peretz, 2006) or the right (Mandell, Schulze, & Schlaug, 2007). An understanding of how these biological differences relate to the behavioural deficits previously mentioned is currently far from clear, but the finding of morphological differences outside the temporal cortex are congruent with findings from functional imaging studies showing activation of frontal and temporal areas when pitch information must be integrated or compared over time (Gaab, Gaser, Zaehle, Jancke, & Schlaug, 2003;Koelsch et al, 2009;Levitin & Menon, 2003;Zatorre, Evans, & Meyer, 1994).…”

Decrease in early right alpha band phase synchronization and late gamma band oscillations in processing syntax in music

“…More specifically, functional imaging studies indicate that areas of the auditory cortex within the right superior temporal gyrus are involved in r Oscillations and Synchronization in Musical Syntax r r 1221 r the processing of pitch and timbre [Zatorre, 1988;Zatorre and Samson, 1991], and that working memory for pitch entails interaction between temporal and frontal cortices [Zatorre et al, 1994]. Hyde et al [2006] found, in the brains of individuals with amusia (tone deafness), white matter changes in the right IFG area (BA 47) as correlates of a musical pitch processing, which was interpreted as an anomalous connectivity between frontal and auditory cortical areas. A PET study [Blood et al, 1999] reported positive correlations of activity in orbitofrontal and bilateral frontopolar cortex with increasing dissonance, and the predominance of inferior frontal areas has been further demonstrated in an fMRI study investigating musical syntax processing where activation of this region increased for strong musical expectancy violations [Tillmann et al, 2003], but also for more subtle harmonic irregularities [Tillmann et al, 2006].…”

The Experience of Music in Congenital Amusia

“…Used to describe individuals born with a lifelong musical impairment, empirical work into the condition has confirmed that amusia is a genuine perceptual agnosia, characterized by deficits in melody recognition and discrimination (Stewart, von Kriegstein, Warren, & Griffiths, 2006). Neuroimaging studies have suggested that the musical difficulties observed in individuals with amusia are related to subtle differences in brain structure and connectivity (Hyde, Zatorre, Griffiths, Lerch, & Peretz, 2006;Loui, Alsop, & Schlaug, 2009;Mandell, Schulze, & Schlaug, 2007) and the condition appears to be hereditary (Drayna, Manichaikul, de Lange, Snieder, & Spector, 2001;Peretz, Cummings, & Dubé, 2007).…”