White Matter Connectivity As A Neurophysiological Mechanism For Auditory Comprehension In The Neurologically Normal And Impaired

Objectives: As emerging brain imaging technologies enable research on white matter connectivity, studies have shown the importance of white matter tracts pertaining to auditory comprehension. The present study aimed to review the recent studies by looking at the relationship between white matter connectivity and language comprehension in several populations. Methods: A literature search identified 19 studies on the relationship between white matter connectivity and auditory comprehension in normal adults and patients with stroke and primary progressive aphasia. Results: Previous studies were analyzed and discussed in terms of phonological, semantic, and syntactic comprehension. Results indicated that dorsal tracts are mainly involved in phonological and syntactic comprehension, while ventral tracts in semantic and syntactic comprehension. In both normal and impaired groups, the arcuate fasciculus is involved in phonological processing, while the uncinated fasciculus, inferior longitudinal fasciculus, extreme capsule, fornix, and arcuate fasciculus are important in semantic comprehension. In syntactic comprehension, the superior longitudinal fasciculus and arcuate fasciculus play an important role. Auditory comprehension problems are affected by the extent to which white matter tracts are damaged. Several limitations of the previous research were also discussed. Conclusion: Further studies on the relationship between white matter connectivity and auditory comprehension need to consider such factors as participants, tasks, and scoring systems.