Computational protocol: Extraversion Is Linked to Volume of the Orbitofrontal Cortex and Amygdala

Similar protocols

Protocol publication

[…] VBM following the Diffeomorphic Anatomical Registration Through Exponentiated Lie (DARTEL) algebra software implemented in Matlab 7.1.0 (The Matlab Inc, Natick, MA, http://www.mathworks.com/) was used. The preprocessing and masking procedure is described in detail elsewhere . Briefly, after segmentation, data were registered, normalized, and modulated using the DARTEL pipeline. Grey matter (GM) images were normalized to Montreal Neurological Institute (MNI) space and smoothed at 8 mm full width at half maximum (FWHM). In the resulting images, each voxel represents an absolute amount of brain volume, equivalent to the brain volume per unit prior to normalization.Next, we performed a multiple regression analysis with neuroticism and extraversion as independent variables and voxel-wise GM density maps as the dependent factor. In addition, sex×personality interaction terms were calculated by setting up a flexible factorial design. In each model, age, scan center, and GM total volumes were entered as nuisance variables. Based on the literature on emotion processing in affective disorders , we set the following regions of interest (ROI): amygdala, orbitofrontal cortex (OFC), anterior cingulate cortex (ACC). A family wise error (FWE) at p<.05 correction for the spatial extent of the ROIs (small volume corrections) was applied. The ROIs were defined by the Automated Anatomical Labeling (AAL) templates implemented in the Wake Forest University School of Medicine (WFU) pickatlas . For regions other than the ROIs, a voxel level threshold of p<.05 whole brain FWE corrected was set a priori. For completeness, explorative analysis are performed at an uncorrected threshold of p<.001, with a spatial cluster extent of 25 contiguous voxels. Demographic and clinical data were analyzed with SPSS 16.0 (http://www-01.ibm.com/software/analytics/spss/) and significance was set at p<.05. […]

Pipeline specifications

Software tools AAL, SPSS
Applications Miscellaneous, Magnetic resonance imaging