Article

Effects of handedness and sex on the morphology of the corpus callosum: a study with brain magnetic resonance imaging.

Neurological Clinic, C.H.U. Timone, Marseilles, France.
Brain and Cognition (Impact Factor: 2.68). 06/1991; 16(1):41-61. DOI: 10.1016/0278-2626(91)90084-L
Source: PubMed

ABSTRACT In view of conflicting data in the existing literature, we examined 53 normal subjects using a handedness questionnaire and callosal area measurements obtained from midsagittal MRI images. The callosum was found to be significantly larger in nonconsistent right-handers (NCRH), especially in its anterior half and especially for males. A significant hand x sex interaction, favoring consistent right-handed (CRH) females, was also found for the posterior midbody, a region known to house interhemispheric fibers connecting the right and left posterior association cortices. These results (1) confirm Witelson's (1985) first findings on postmortem specimens; (2) validate a dichotomy between CRH and NCRH rather than simply considering the writing hand, as was the case in most other similar studies; and (3) suggest that at least two different sex-related--probably hormonal--factors may be acting during the callosal development, one explaining the larger anterior half in NCRH males and the other the larger posterior midbody in CRH females.

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