Co-localizing linguistic and musical syntax with intracranial EEG

Abstract

Despite general agreement on shared syntactic resources in music and language, the neuroanatomical underpinnings of this overlap remain largely unexplored. While previous studies mainly considered frontal areas as supramodal grammar processors, the domain-general syntactic role of temporal areas has been so far neglected. Here we capitalized on the excellent spatial and temporal resolution of subdural EEG recordings to co-localize low-level syntactic processes in music and language in the temporal lobe in a within-subject design. We used Brain Surface Current Density mapping to localize and compare neural generators of the early negativities evoked by violations of phrase structure grammar in both music and spoken language. The results show that the processing of syntactic violations relies in both domains on bilateral temporo-fronto-parietal neural networks. We found considerable overlap of these networks in the superior temporal lobe, but also differences in the hemispheric timing and relative weighting of their fronto-temporal constituents. While alluding to the dissimilarity in how shared neural resources may be configured depending on the musical or linguistic nature of the perceived stimulus, the combined data lend support for a co-localization of early musical and linguistic syntax processing in the temporal lobe.

Neural correlates of expectation of musical termination structure or cadence

“…Many previous studies have reported on brain activity elicited by violations of cadences caused by replacing T chords with other irregular chords [1,[10][11][12]16]. The difference in neural responses to less-expected chords compared with expected chords appeared as P3, an early right anterior negativity, or as a late frontal negativity (N5).…”

“…Much neuroscience research on the recognition of musical termination has been concerned with neural activity following the expectancy violation of musical cadences [10][11][12]. These reports show that the chord sequence of the cadence elicits a strong expectation of a T chord at the end of the sequence that induces music termination.…”

Neural overlap in processing music and speech

“…Using this method to examine the contribution of the STGs to the linguistic and musical syntax, Sammler et al [47] compared the early negativities evoked by violations of structure in sentences and chord sequences in five patients. The results showed considerable overlap in the bilateral STG, but also differences in the hemispheric timing and relative involvement of the frontal and temporal brain structures.…”

Recursion in action: An fMRI study on the generation of new hierarchical levels in motor sequences

“…Numerous studies in the domains of language, music, and vision have investigated the discrimination of hierarchical structures by asking participants to evaluate whether sequences of items are well‐formed according to a previously learned system of rules (Bahlmann, Schubotz, & Friederici, ; Bahlmann, Schubotz, Mueller, Koester, & Friederici, ; Bianco et al, ; Friederici, Bahlmann, Friedrich, & Makuuchi, ; Maess, Koelsch, Gunter, & Friederici, ; Sammler, Koelsch, & Friederici, ). These studies suggest that lateral prefrontal cortex (PFC, particularly inferior frontal gyrus, IFG) might contribute multi‐domain resources to the processing of hierarchies (Fadiga, Craighero, & D'Ausilio, ; Friederici et al, ; Patel, ), in interaction with areas along ventral visual/auditory streams that may store domain‐specific schematic information (Bianco et al, ; Martins et al, ; Oechslin, Gschwind, & James, ; Pallier, Devauchelle, & Dehaene, ; Sammler et al, ). Recent anatomical research has shown that IFG in humans is expanded (Schenker et al, ) and more strongly connected with the posterior temporal regions in comparison to other primates (Neubert, Mars, Thomas, Sallet, & Rushworth, ; Rilling et al, ).…”