Is Handedness Associated with the Depth of the Olfactory Sulcus?

Is Handedness Associated with the Depth of the Olfactory Sulcus?: Background: Structural and functional asymmetry is frequent in biological systems. The aim of the present study was to examine whether there is a relation between handedness and the depth of the olfactory sulcus (OS) and reinvestigate whether there is a lateralization of OS depth. Methods: Forty-two healthy volunteers (mean age 24.1 years; 23 right-handed and 19 left-handed) participated. The subjects’ brains were scanned using magnetic resonance imaging to assess OS depth. Normal olfactory function was ascertained using the Sniffin’ Sticks odor identification test. Results: There was no significant difference in OS depth between right- and left-handed participants (right-handed mean: right OS depth = 11.3 mm, left OS = 10.6 mm; left-handed mean: right OS = 11.3 mm, left OS = 11.0 mm). Across all subjects, OS depth was significantly larger on the right side compared to the left. Conclusion: Handedness has no major influence on OS depth. The present study confirmed that the right OS is deeper compared to the left OS, possibly indicating a right-sided lateralization of the olfactory system. Implications: The depth of the right OS is larger than that of the left OS. No major effect of handedness was observed.

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