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РОЛИ ОТДЕЛЬНЫХ СЕГМЕНТОВ ДУГООБРАЗНОГО ПУЧКА В ОБЕСПЕЧЕНИИ ЯЗЫКОВОЙ ОБРАБОТКИ
The connectivity between perisylvian language areas is subserved by three segments of the arcuate fasciculus (AF): the long segment, connecting posterior temporal and inferior frontal areas; and anterior and posterior segments, connecting the inferior frontal lobule to inferior frontal and posterior temporal areas, respectively. Disconnection of the long segment of the AF is known to give rise to conduction aphasia, manifesting itself in impaired repetition due to a deficit in sensorimotor integration. Systematic analyses of the specific contributions of the three segments of the AF to language processing are, however, lacking. The current study is the first to address the roles of these white-matter tracts in language production and comprehension at various linguistic levels. We found that a lower volume of the long AF segment following neurosurgery is associated with greater deficits in language production and repetition, consistent with the tract’s well-established role in sensorimotor integration. We did not find any relation between the volumes of the an-
terior and posterior AF segments and language deficits. One plausible explanation is that these tracts are not critical for language processing, whereas the functions they underlie in healthy speakers demonstrate a greater capacity for reorganization during the slow growth of a glioma, as opposed to those carried out by the long AF segment.