Mapping the Arcuate Fasciculus with nTMS and Action Naming: the Effect of Transitivity
EasyChair Preprint 6512
6 pages•Date: August 31, 2021Abstract
Introduction
Language mapping with navigated Transcranial Magnetic Stimulation (nTMS) is used to identify cortical areas involved in language processing (Picht et al., 2013). The combination of diffusion Magnetic Resonance Imaging (dMRI) and nTMS can increase language mapping accuracy by allowing researchers to stimulate cortical terminations of white matter tracts (Reisch et al., subm.). Cortical regions connected by the arcuate fasciculus (AF) have been shown to be involved in the processing of transitive and unergative verbs, with transitive verb processing eliciting higher BOLD activation bilaterally (den Ouden et al., 2009; Shetreet et al., 2007; Thompson et al., 2007, 2010).
Methods
In the present study, we combined dMRI and nTMS during an action naming task with finite verbs (Ohlerth et al., 2020) to investigate the neural underpinnings of transitive and unergative verbs. After performing fiber tracking of the left and right AF, we stimulated frontal, parietal, and temporal cortical terminations in 10 healthy participants. Based on previous findings, we predicted that if verb production is influenced by the number of arguments, nTMS will induce more errors during naming of transitive compared to unergative verbs.
Results
Induced errors were analysed according to cortical terminations and verb type. Only for the left AF, results suggest that nTMS induced more errors with transitive verbs compared to unergative verbs when stimulating temporal terminations.
Conclusions
Preliminary data suggest that suppression of posterior temporal regions leads to increased error rates during the production of transitive verbs. Given the inhibitory nature of our nTMS protocol and in line with previous work (den Ouden et al., 2009; Matchin et al., 2019; Thompson et al., 2010), we show that posterior temporal regions are causally involved in argument structure processing.
Keyphrases: Arcuate fasciculus, action naming, language mapping, nTMS, transitivity