3 t 750 mri scanner

Subjects were scanned on a 3T 750 MRI scanner (General Electric, Milwaukee, WI) with a 32-channel head coil. Acquisitions were performed using an echo-planar imaging (EPI) sequence of 40 contiguous sagittal slices per brain volume (TR = 2000 ms, TE = 25 ms, flip angle = 60° slice thickness = 4.0 mm). In-plane resolution was 3.75 × 3.75 mm (64 × 64 voxels). An fMRI task presentation of the 32 questions was created using E-Prime software (Psychology Software Tools, Inc.) and displayed via a goggle system (Nordic NeuroLab Inc., Milwaukee, WI) while each participant was in the fMRI scanner. The questions were presented in random order for each subject over the course of four fMRI acquisition runs, with eight questions per run. The mean run length (± standard deviation) was 392 ± 62 sec. During the same imaging session, a high-resolution T1-weighted image was acquired for anatomical reference (three dimensional GRE; TR = 6.6 ms, TE = 2.5 ms, flip angle = 12°). This image consisted of 312 sagittal slices with a slice thickness of 0.6 mm and an in-plane resolution of 0.468 × 0.468 mm (512 × 512 voxels). For voxel-wise analysis on whole brain data, we controlled false positive rates per map at alpha=0.05, using random-effects models and consistent with prior work.