A voxel-based morphometry study of frontal gray matter correlates of impulsivity

Autor: Fabiano G. Nery, Kiyotaka Nemoto, Marco Aurélio Monteiro Peluso, Mark Nicoletti, John P. Hatch, Jair C. Soares, Koji Matsuo
Rok vydání: 2009
Předmět:
Zdroj: Hum Brain Mapp
ISSN: 1097-0193
1065-9471
DOI: 10.1002/hbm.20588
Popis: Impulsivity is a personality trait exhibited by healthy individuals, but excessive impulsivity is associated with some mental disorders. Lesion and functional neuroimaging studies indicate that the ventromedial prefrontal region (VMPFC), including the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and medial prefrontal cortex, and the amygdala may modulate impulsivity and aggression. However, no morphometric study has examined the association between VMPFC and impulsivity. We hypothesized that healthy subjects with high impulsivity would have smaller volumes in these brain regions compared with those with low impulsivity. Sixty‐two healthy subjects were studied (age 35.4 ± 12.1 years) using a 1.5‐T MRI system. The Barratt impulsiveness scale (BIS) was used to assess impulsivity. Images were processed using an optimized voxel‐based morphometry (VBM) protocol. We calculated the correlations between BIS scale scores and the gray matter (GM) and white matter (WM) volumes of VMPFC and amygdala. GM volumes of the left and right OFC were inversely correlated with the BIS total score (P = 0.04 and 0.02, respectively). Left ACC GM volumes had a tendency to be inversely correlated with the BIS total score (P = 0.05). Right OFC GM volumes were inversely correlated with BIS nonplanning impulsivity, and left OFC GM volumes were inversely correlated with motor impulsivity. There were no significant WM volume correlations with impulsivity. The results of this morphometry study indicate that small OFC volume relate to high impulsivity and extend the prior finding that the VMPFC is involved in the circuit modulating impulsivity. Hum Brain Mapp 2009. © 2008 Wiley‐Liss, Inc.
Databáze: OpenAIRE