Imaging data analyses were conducted through FEAT (FMRI Expert Analysis Tool) version 5.43, part of FSL (FMRIB Software Library). Standard preprocessing was applied, including nonbrain removal using the Brain Extraction Tool method,39 spatial smoothing using a gaussian kernel of full width at half maximum of 8-mm, mean-based intensity normalization of all volumes by the same factor and high-pass temporal filtering (σ = 50.0 seconds). Time series statistical analysis was performed using FMRIB’s Improved Linear Model with local autocorrelation correction.40 Regressors were created by convolving the stimulus timing files with a double γ-variate hemodynamic response function. A multiple linear regression analysis was performed to estimate the hemodynamic parameters for different explanatory variables (ie, alcohol taste period, control taste period, and baseline period), and a corresponding t statistic indicated the significance of the activation of the stimulus. The primary contrast was the alcohol vs control taste period. For comparisons between genotype groups, these contrast maps were then registered to a high-resolution image using FMRIB’s Linear Image Registration Tool. A priori region-of-interest anatomical masks were created using previously described methods35 for the NAcc/ventral
