Resource scarcity aggravates ingroup bias: neural mechanisms and cross-scenario validation

ACC activation reflects a conflict between self-oriented and other-oriented motives during resource allocation, which is modulated by mentalizing toward ingroup over outgroup in the scarcity condition. Finally, the ACC activation level significantly predicted the influence of resource scarcity on ingroup bias in hypothetical real-life situations according to a follow-up examination.We used a Siemens Prisma 3.0 T MRI machine for data acquisition.

Functional volumes were acquired using a multiple slice T2-weighted echo planar imaging (EPI) sequences with the following parameters: repetition time = 1500 ms, echo time = 30 ms, flip angle = 75°, field of view = 192 × 192 mm2, 72 slices covering the entire brain, slice thickness = 2 mm, voxel size = 2 × 2 × 2 mm3.fMRI data were preprocessed in SPM12 (Wellcome Department of Imaging Neurosciences, University College London, U.K., fil.ion.ucl.ac.uk/spm).

Functional data sets underwent slice timing correction, motion correction, were normalized to Montreal Neurological Institute (MNI) space with a spatial resolution of 2 × 2 × 2 mm3, and were smoothed with an isotropic Gaussian kernel of 6 mm and high-pass filtered at a cutoff of 128 s.Behavioral data were processed in IBM SPSS Statistics 20.0.