fMRI data analysis Preprocessing The imaging data was preprocessed and analyzed using the image processing routines implemented within the statistical parametric mapping software package, SPM8 (http://www.fil.ion.ucl.ac.uk/spm/software/spm8/; Wellcome Trust Centre for Neuroimaging). Images for each subject were first corrected for selleck kinase inhibitor susceptibility-by-movement artifacts and then realigned to the first volume of the time series. Realigned images were spatially normalized into a standard stereotactic space (Montreal Neurologic Institute template) and smoothed

with a Gaussian kernel (FWHM 8 mm) in order to minimize anatomical differences. Inhibitors,research,lifescience,medical The BOLD response at each voxel was modeled with a canonical hemodynamic response function and its temporal derivative. Effects of emotional stimuli For each participant, brain activation was examined for the contrasts of the emotional (positive, negative, and interesting) Inhibitors,research,lifescience,medical images relative to the nonemotional landscape images: emotional > nonemotional. These individual contrast

images were then used in the second-level random effects model in order to determine regional responses Inhibitors,research,lifescience,medical for the whole sample. We conducted a whole-brain analysis in order to ensure the emotion processing task activated regions associated with emotional processing, and critically, our regions of interest (ROIs) including the bilateral rACC (operationally defined as the portion Inhibitors,research,lifescience,medical of anterior cingulate that lies anterior and superior to the genu of the corpus callosum, with the posterior boundary of y = +30 mm; Bryant et al. 2005) and the left and right AMY (as previously defined; Tzourio-Mazoyer et al. 2002; Maldjian et al. 2003). The rACC was defined bilaterally as clusters on the left or right rACC may be indistinguishable

due to low spatial resolution at 3 mm. For all analyses, we employed Inhibitors,research,lifescience,medical an alpha level of P < 0.05 (partial volume, FDR-corrected) and a spatial extent of five or more voxels per cluster in order to control for type I error rates associated with multiple comparisons within secondly the ROIs. The bilateral rACC and left and right AMY ROIs were subsequently employed in the analyses examining gene effects. Total gene effects, main effect of 5-HTTLPR, and main effect of BDNF Val66Met effect on emotional stimuli In order to determine whether there were effects of genotype, an omnibus analysis of variance (ANOVA) on the emotional > nonemotional contrast was performed for the ROIs rACC and AMY. Consequently, a second ANOVA was performed for the emotional > nonemotional contrast in order to determine whether there was an effect of the 5-HTTLPR genotype (S and L/L groups) within the rACC and AMY ROIs. These analyses were then followed up with independent samples t-tests in order to determine the directions of the effects.