White matter association tracts underlying language and theory of mind: An investigation of 809 brains from the Human Connectome Project

• Authors: Leo R Zekelman, Harvard Medical School; Fan Zhang, Emory University; Nikos Makris, Boston University; Jianzhong He, Harvard Medical School; Yuqian Chen, Harvard Medical School; Tengfei Xue, Harvard Medical School; Daniela Liera, Harvard University; Daniel Drane, Emory University; Yogesh Rathi, Harvard Medical School; Alexandra J Golby, Harvard Medical School; Lauren J O'Donnell, Harvard Medical School
• Journal Title: NEUROIMAGE
• Volume: Volume 246
• Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE | 2021-12-10, Pages 118739-118739
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1016/j.neuroimage.2021.118739
• Subjects: Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Neurosciences; Neuroimaging; Radiology, Nuclear Medicine & Medical Imaging; Neurosciences & Neurology; White matter tractography; Diffusion MRI; Human Connectome Project; Semantic memory; Emotion perception; Association white matter; MIDDLE LONGITUDINAL FASCICLE; INFERIOR FRONTAL GYRUS; ARCUATE FASCICULUS; IN-VIVO; FUNCTIONAL SEGREGATION; EMOTION RECOGNITION; FIBER TRACTOGRAPHY; PRETERM CHILDREN; TEMPORO-PARIETAL; SEX-DIFFERENCES

Abstract

Language and theory of mind (ToM) are the cognitive capacities that allow for the successful interpretation and expression of meaning. While functional MRI investigations are able to consistently localize language and ToM to specific cortical regions, diffusion MRI investigations point to an inconsistent and sometimes overlapping set of white matter tracts associated with these two cognitive domains. To further examine the white matter tracts that may underlie these domains, we use a two-tensor tractography method to investigate the white matter microstructure of 809 participants from the Human Connectome Project. 20 association white matter tracts (10 in each hemisphere) are uniquely identified by leveraging a neuroanatomist-curated automated white matter tract atlas. The fractional anisotropy (FA), mean diffusivity (MD), and number of streamlines (NoS) are measured for each white matter tract. Performance on neuropsychological assessments of semantic memory (NIH Toolbox Picture Vocabulary Test, TPVT) and emotion perception (Penn Emotion Recognition Test, PERT) are used to measure critical subcomponents of the language and ToM networks, respectively. Regression models are constructed to examine how structural measurements of left and right white matter tracts influence performance across these two assessments. We find that semantic memory performance is influenced by the number of streamlines of the left superior longitudinal fasciculus III (SLF-III), and emotion perception performance is influenced by the number of streamlines of the right SLF-III. Additionally, we find that performance on both semantic memory & emotion perception is influenced by the FA of the left arcuate fasciculus (AF). The results point to multiple, overlapping white matter tracts that underlie the cognitive domains of language and ToM. Results are discussed in terms of hemispheric dominance and concordance with prior investigations.