Differences in regional brain volume related to the extraversion-introversion dimension--a voxel based morphometry study.
Extraverted individuals are sociable, behaviorally active, and happy. We report data from a voxel based morphometry study investigating, for the first time, if regional volume in gray and white matter brain regions is related to extraversion. For both gray and white matter, all correlations between extraversion and regional brain volume were negative, i.e. the regions were larger in introverts. Gray matter correlations were found in regions that included the right prefrontal cortex and the cortex around the right temporo-parietal junction--regions that are known to be involved in behavioral inhibition, introspection, and social-emotional processing, e.g. evaluation of social stimuli and reasoning about the mental states of others. White matter correlations extended from the brainstem to widespread cortical regions, and were largely due to global effects, i.e. a larger total white matter volume in introverts. We speculate that these white matter findings may reflect differences in ascending modulatory projections affecting cortical regions involved in behavioral regulation.
Neuropediatric Research Unit, Department of Women's and Children's Health, Karolinska Institutet and Stockholm Brain Institute, SE-171 76, Sweden. Lea.Forsman@ki.se
Lea J
LJ
Forsman
Orjan
O
de Manzano
Anke
A
Karabanov
Guy
G
Madison
Fredrik
F
Ullén
D000328:Adult; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D005120:Extraversion, Psychological; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007439:Introversion, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017397:Prefrontal Cortex / Q000502:physiology