Gender differences in the left inferior frontal gyrus in normal children.

This study examined frontal lobe subregions in 46 normal children and adolescents (25 females, mean age: 11.08, SD: 3.07; and 21 males, mean age: 10.76, SD: 2.61) to assess the effects of age and gender on volumetric measures as well as hemispheric asymmetries. Superior, middle, inferior, and orbito-frontal gray, white, and cerebrospinal (CSF) volumes were manually delineated in high-resolution magnetic resonance imaging (MRI) data to assess possible morphological changes. We report a significant age-related increase in the white matter of the left inferior frontal gyrus (IFG) in boys (P = 0.007). Additionally, the left IFG was significantly larger in boys compared to girls (P = 0.004). Boys showed increased gray matter volume relative to girls even after correcting for total cerebral volume. Also, boys were found to have significant Right > Left asymmetry patterns with greater right hemispheric volumes for total cerebral volume, total cerebral white matter, MFG white matter, and SFG white matter (P < 0.001). Girls showed significant Right > Left asymmetry patterns in total cerebral and SFG white matter (P < 0.001). These findings suggest continued modification of the IFG during normal development in boys, and significant gender differences in IFG gray matter between boys and girls that may be possibly linked to gender differences in speech development and lateralization of language.