Diminished Whole-brain but Enhanced Peri-sylvian Connectivity in Absolute Pitch Musicians

Abstract

Several anatomical studies have identified specific anatomical features within the peri-sylvian brain system of absolute pitch (AP) musicians. In this study we used graph theoretical analysis of cortical thickness covariations (as indirect indicator of connectivity) to examine whether AP musicians differ from relative pitch musicians and nonmusicians in small-world network characteristics. We measured "local connectedness" (local clustering = ), "global efficiency of information transfer" (path length = ), "small-worldness" ( = /), and "degree" centrality as measures of connectivity. Although all groups demonstrated typical small-world features, AP musicians showed significant small-world alterations. "Degree" as a measure of interconnectedness was globally significantly decreased in AP musicians. These differences let us suggest that AP musicians demonstrate diminished neural integration (less connections) among distant brain regions. In addition, AP musicians demonstrated significantly increased local connectivity in peri-sylvian language areas of which the planum temporale, planum polare, Heschl's gyrus, lateral aspect of the superior temporal gyrus, STS, pars triangularis, and pars opercularis were hub regions. All of these brain areas are known to be involved in higher-order auditory processing, working or semantic memory processes. Taken together, whereas AP musicians demonstrate decreased global interconnectedness, the local connectedness in peri-sylvian brain areas is significantly higher than for relative pitch musicians and nonmusicians. ical features within the peri-sylvian brain system of absolute pitch (AP) musicians. In this study we used graph theoretical analysis of cortical thickness covariations (as indirect indicator of connectivity) to examine whether AP musicians differ from relative pitch musicians and nonmusicians in small-world network characteristics. We measured "local connectedness" (local clustering = γ), "global efficiency of information transfer" (path length = λ), "small-worldness" (σ = γ/λ), and "degree" centrality as measures of connectivity. Although all groups demonstrated typical small-world features, AP musicians showed significant small-world alterations. "Degree" as a measure of interconnectedness was globally significantly decreased in AP musicians. These differences let us suggest that AP musicians demonstrate diminished neural integration (less connections) among distant brain regions. In addition, AP musicians demonstrated significantly increased local connectivity in peri-sylvian language areas of which the planum temporale, planum polare, Heschlʼs gyrus, lateral aspect of the superior temporal gyrus, STS, pars triangularis, and pars opercularis were hub regions. All of these brain areas are known to be involved in higherorder auditory processing, working or semantic memory processes. Taken together, whereas AP musicians demonstrate decreased global interconnectedness, the local connectedness in perisylvian brain areas is significantly higher than for relativ...

An Empirical Reevaluation of Absolute Pitch: Behavioral and Electrophysiological Measurements

“…However, to date there is growing evidence indicating that these two processes are mediated by distinctive brain regions and associated with specific anatomical white (Loui et al, 2011;Oechslin et al, 2010) and gray (Wengenroth et al, 2013;Jäncke et al, 2012) matter architectures. In fact, in a very recent study, Wengenroth et al (2013) used functional and structural MRI, as well as magnetoencephalography and could show that gray matter volume of the right Heschlʼs gyrus was highly correlated with AP proficiency.…”

“…Currently, there is some evidence showing that the left arcuate fasciculus, which is a fiber bundle stretching from the posterior supratemporal plane to frontal brain regions, may facilitate conceptual associations between auditory information and the corresponding labels (Loui, Li, Hohmann, & Schlaug, 2011;Oechslin, Imfeld, Loenneker, Meyer, & Jancke, 2010). Furthermore, it is still unclear whether small-world properties (i.e., local connectedness and global efficiency of information transfer) of left peri-sylvian brain regions may account for the more distinctive conceptual associations of AP musicians (Jäncke, Langer, & Hänggi, 2012;Loui, Zamm, & Schlaug, 2012) and whether cortical hyperconnectivity of superior temporal regions is specific to AP rather than to savant skills in general (Loui et al, 2011).…”

Absolute Pitch: Evidence for Early Cognitive Facilitation during Passive Listening as Revealed by Reduced P3a Amplitudes

“…In this context, AP participants were shown to exhibit altered neurophysiological responses during early stages of auditory processing (Matsuda et al, 2013;Schulze, Gaab, & Schlaug, 2009;Wu, Kirk, Hamm, & Lim, 2008;Itoh, Suwazono, Arao, Miyazaki, & Nakada, 2005;Ohnishi et al, 2001;Hirata, Kuriki, & Pantev, 1999). In addition, there is some evidence pointing to a differential structural architecture in the brain networks of AP participants involved in the early stage of auditory processing (Wengenroth et al, 2013;Jäncke, Langer, & Hänggi, 2012;Loui, Zamm, & Schlaug, 2012;Loui, Li, Hohmann, & Schlaug, 2011;Oechslin, Imfeld, Loenneker, Meyer, & Jäncke, 2010;Bermudez, Lerch, Evans, & Zatorre, 2009;Wilson, Lusher, Wan, Dudgeon, & Reutens, 2009;Luders, Gaser, Jancke, & Schlaug, 2004;Keenan, Thangaraj, Halpern, & Schlaug, 2001;Schlaug, 2001;Schlaug, Jancke, Huang, & Steinmetz, 1995). Nevertheless, to date it is still a matter of debate whether the specificity of the first processing stage is restricted to AP participants only.…”

Neurobiological basis of head motion in brain imaging

“…Specifically, individual differences in brain connectivity could determine how well a subject can lie still in the scanner. This is not unreasonable as individual differences in structural connectivity can predict trait anxiety and can be related to attention deficits (17, 18) and individual differences in resting-state functional MRI (fMRI) measures may relate to various behavioral differences, including impulsivity (19)(20)(21)(22). In such a scenario, certain intersubject differences in connectivity measures could persist even after the most rigorous motion correction, as has been suggested in several earlier studies (23,24).…”