Functional Connectome Correlates of Laterality Preferences: Insights into Hand, Foot, and Eye Dominance across the Lifespan.

Tejavibulya L., Horien C., Fredericks C., Ficek B., Westwater ML., Scheinost D.

Humans exhibit laterality preferences, with handedness being the most extensively studied. Accordingly, brain-handedness associations are well documented. However, laterality preferences extend beyond handedness to include other limbs, such as footedness and eyedness. Despite these distinctions, brain-footedness and brain-eyedness associations using resting-state functional connectomes remain largely unexplored. We utilize two large datasets, the Human Connectome Project-Development (HCP-D) and Human Connectome Project-Aging (HCP-A), to study the associations between sidedness (i.e., handedness, footedness, and eyedness) and whole-brain functional connectomes. While hand and foot preferences were correlated significantly, they explained <40% of the variance, suggesting some distinctions between measures. For both cohorts, significant associations between handedness connectivity were observed [p < 0.05, network-based statistics (NBS) corrected]. Notable patterns include increased connectivity for left-handedness in the posterior temporal areas and right-handedness in cerebellar regions. In contrast, significant associations between footedness and handedness connectivity were observed only in the HCP-A (p < 0.05, NBS corrected) and not the HCP-D. No significant associations between eyedness and connectivity were observed for either group. Finally, we compared the effect size between brain-handedness and brain-footedness associations. A greater difference was found in the HCP-D. The two cohorts primarily differed in edge distribution in the prefrontal lobe, temporal lobe, and cerebellum. Overall, in adults, brain-handedness and brain-footedness associations were similar. However, in children to adolescents, brain-handedness and brain-footedness associations diverge, suggesting a developmental shift. Characterizing sidedness associations with whole-brain connectomes may provide important insights into understanding the motor and visual systems, rehabilitation and occupational therapy, and benchmarking normative variations in the connectome.

DOI

10.1523/ENEURO.0580-24.2025

Type

Journal article

Publication Date

2025-07-01T00:00:00+00:00

Volume

12

Keywords

brainwide associations, eyedness, footedness, functional connectivity, handedness, Humans, Connectome, Functional Laterality, Male, Female, Adult, Brain, Middle Aged, Young Adult, Magnetic Resonance Imaging, Aged, Foot, Adolescent, Child, Dominance, Ocular, Hand, Longevity

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