Sensitivity to word structure in adult Hebrew readers is associated with microstructure of the ventral reading pathways

Abstract

Skilled readers differ in their sensitivity to morphological word structure, which captures useful regularities in the mapping between written word forms and their meaning. We recently showed that sensitivity to morphological information in adult English readers is associated with the ventral reading pathways, bilaterally. It remains unclear, however, whether this association is specific to the English writing system. To shed light on this question, we investigated whether the associations between the ventral reading pathways and morphological sensitivity to word structure generalize across languages with different orthographies and morphological systems. To this end, we assessed neurocognitive correlations between white matter structural properties and morphological sensitivity in Hebrew, a Semitic language where morphemes are combined in a non-linear manner. We used diffusion MRI (dMRI) to segment ventral and dorsal tracts of interest in a sample of 43 adult Hebrew readers, who also completed a behavioral language assessment battery that included a morphological task. Significant correlations were found between morphological sensitivity and properties of bilateral ventral, but not dorsal, tracts. These correlations remained significant after controlling for measures of vocabulary and word reading, demonstrating their specificity to the morphological task. The current findings in Hebrew show striking similarity to prior findings in English. Our results support the view that morphological information contributes to lexical access along the ventral pathways, across orthographies and morphological systems.

Keywords: DTI; Derivational morphology; Diffusion imaging; Hebrew; Morphological processing; Reading; White matter tractography.