Abstract
The ability to recognize the structural components of words, known as morphological processing, was recently associated with the bilateral ventral white matter pathways, across different writing systems. However, it remains unclear whether these associations are specific to the context of reading. To shed light on this question, in the current study we investigated whether the ventral pathways are associated with morphological processing in an oral word production task that does not involve reading. Forty-five participants completed a morpheme-based fluency task in Hebrew, as well as diffusion MRI (dMRI) scans. We used probabilistic tractography to segment the major ventral and dorsal white matter pathways, and assessed the correlations between their microstructural properties and performance on the morpheme-based fluency task. We found significant correlations between morpheme-based fluency and properties of the bilateral ventral tracts, suggesting that the involvement of these tracts in morphological processing extends beyond the reading modality. In addition, significant correlations were found in the frontal aslant tract (FAT), a dorsal tract associated with oral fluency and speech production. Together, our findings emphasize that neurocognitive associations reflect both the cognitive construct under investigation as well as the task used for its assessment. Lastly, to elucidate the biological factors underlying these correlations, we incorporated the composite hindered and restricted model of diffusion (CHARMED) framework, measured in independent scans. We found that only some of our findings could be attributed to variation in a CHARMED-based estimate of fiber density. Further, we were able to uncover additional correlations that could not be detected using traditional dMRI indices. In sum, our results show that the involvement of the ventral tracts in morphological processing extends to the production domain, and demonstrate the added value of including sensitive structural measurements in neurocognitive investigations.
Original language | English |
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Article number | 117577 |
Journal | NeuroImage |
Volume | 226 |
DOIs | |
State | Published - 1 Feb 2021 |
Bibliographical note
Funding Information:This study was conducted as part of Maya Yablonski's doctoral dissertation, carried under the supervision of Prof. Michal Ben-Shachar at the Gonda Multidisciplinary Brain Research Center, Bar-Ilan University. This study was supported by the Israel Science Foundation (ISF grant #1083/17), the US-Israel Binational Science Foundation (BSF grant #2011314) and the center for research excellence in cognitive science (I-CORE Program 51/11). Maya Yablonski was partly supported by the Wolf Foundation. We are grateful to Yaniv Assaf for guidance in implementing the CHARMED protocol and analysis pipeline. We thank Vered Kronfeld-Duenias for assistance in analysis of CHARMED data. We thank Daniel Barazany and the team at the Strauss Center for Computational Neuroimaging for their assistance in protocol setup and MRI scanning. We thank Kathleen Rastle and JSH Taylor for helpful discussions.
Funding Information:
This study was conducted as part of Maya Yablonski's doctoral dissertation, carried under the supervision of Prof. Michal Ben-Shachar at the Gonda Multidisciplinary Brain Research Center, Bar-Ilan University. This study was supported by the Israel Science Foundation (ISF grant #1083/17), the US-Israel Binational Science Foundation (BSF grant #2011314) and the center for research excellence in cognitive science (I-CORE Program 51/11). Maya Yablonski was partly supported by the Wolf Foundation. We are grateful to Yaniv Assaf for guidance in implementing the CHARMED protocol and analysis pipeline. We thank Vered Kronfeld-Duenias for assistance in analysis of CHARMED data. We thank Daniel Barazany and the team at the Strauss Center for Computational Neuroimaging for their assistance in protocol setup and MRI scanning. We thank Kathleen Rastle and JSH Taylor for helpful discussions.
Publisher Copyright:
© 2020
Keywords
- CHARMED
- DTI
- Morphological processing
- Tractography
- Verbal fluency
- White matter