A single dual-stream framework for syntactic computations in music and language Mariacristina Musso a,b, ⁎, Cornelius Weiller a,b , Andreas Horn a,b , Volkmer Glauche a,b , Roza Umarova a,b , Jürgen Hennig c , Albrecht Schneider d , Michel Rijntjes a,b a Freiburg Brain Imaging, University Hospital Freiburg, Germany b Department of Neurology, University Hospital Freiburg, Germany c Department of Radiology, Medical Physics, University Hospital Freiburg, Germany d Institute of Musicology, University of Hamburg, Germany abstract article info Article history: Received 8 April 2015 Accepted 7 May 2015 Available online 19 May 2015 This study is the first to compare in the same subjects the specific spatial distribution and the functional and an- atomical connectivity of the neuronal resources that activate and integrate syntactic representations during music and language processing. Combining functional magnetic resonance imaging with functional connectivity and diffusion tensor imaging- based probabilistic tractography, we examined the brain network involved in the recognition and integration of words and chords that were not hierarchically related to the preceding syntax; that is, those deviating from the universal principles of grammar and tonal relatedness. This kind of syntactic processing in both domains was found to rely on a shared network in the left hemisphere centered on the inferior part of the inferior frontal gyrus (IFG), including pars opercularis and pars triangularis, and on dorsal and ventral long association tracts connecting this brain area with temporo-parietal regions. Lan- guage processing utilized some adjacent left hemispheric IFG and middle temporal regions more than music pro- cessing, and music processing also involved right hemisphere regions not activated in language processing. Our data indicate that a dual-stream system with dorsal and ventral long association tracts centered on a func- tionally and structurally highly differentiated left IFG is pivotal for domain–general syntactic competence over a broad range of elements including words and chords. © 2015 Elsevier Inc. All rights reserved. Introduction In all natural languages and musical styles, meaningful sentences and consonant musical sequences are not made up of haphazardly jux- taposed words or musical tones. Rather, a set of combinatorial principle defines the order in which the individual elements appear and the func- tional roles they play (Koelsch et al., 2007; Jackendoff and Lerdahl, 2006; Koelsch, 2006; Patel, 2003, Chomsky, 1981). Syntax may be de- fined as the set of these combinatorial principles. Knowledge of syntax (when combined with additional relevant information) determines that incoming sequences of individual words or tones are perceived in terms of hierarchical relations, which in turn directs the meaning ex- tracted from the sequence (Jackendoff and Lerdahl, 2006; Patel, 2003; Chomsky, 1981). In language, generative linguists propose that this kind of hierarchy assigns the grammatical role of elements in a sentence, e.g. whether they act as subject or object, rather than the properties of the elements themselves or their bare linear order. Linear order can of course be mod- ified to affect meaning, however this must be done according to the principles of hierarchy (Chomsky, 1981). Moreover, these kinds of prin- ciples (e.g., that a sentence must always have a subject even if it is not overtly pronounced, or that a transitive verb requires an object) define the design characteristics of language, are universal and implicit across languages, and are therefore labeled by generativists as Universal Gram- mar (UG) (Chomsky, 1981). It has been argued that a broad sense of tonality may be a syntactic music universal (Jackendoff and Lerdahl, 2006; Nettl, 2000). As the term “universal” implies, this broad sense of tonality ‘does not require or even imply harmonic progression, and need not be based on Western major and minor scales’ (Jackendoff and Lerdahl, 2006, p.45). Rather it refers to the relationships between musical elements: tones, intervals, chords, and scales (the type depending on the particular music system). Importantly, these relationships are characterized as hierarchical be- cause they are based on different levels of superiority. Lerdahl (2001) spatially maps musical phrases in syntactic trees to illustrate these hierarchical relationships, much like Chomsky (1981) does to show the grammatical relationships in sentences. In all tonal music, one of NeuroImage 117 (2015) 267–283 ⁎ Corresponding author. Fax: +49 0761 2705416. E-mail address: mariachristina.musso@uniklinik-freiburg.de (M. Musso). http://dx.doi.org/10.1016/j.neuroimage.2015.05.020 1053-8119/© 2015 Elsevier Inc. All rights reserved. Contents lists available at ScienceDirect NeuroImage journal homepage: www.elsevier.com/locate/ynimg