A 4-Tesla whole-body Varian/Siemens MRI scanner and a T2*-weighted single-shot gradient-echo planar imaging (EPI) pulse sequence (TE/TR = 20/1600 ms, 4-mm slice thickness, 33 coronal slices, 64×64 matrix size, 3.1×3.1 mm in-plane resolution, 90°-flip angle, 131 time points) were used to map the blood oxygenation level dependent (BOLD) fMRI responses in the whole brain. Padding was used to minimize motion. Subject motion was monitored immediately after each fMRI run using a k-space motion detection algorithm [25] written in IDL (ITT Visual Information Solutions, Boulder, CO). Earplugs (acoustic noise attenuation: 28 dB; Aearo Ear TaperFit 2; Aearo Company) and headphones (acoustic noise attenuation: 30 dB; Commander XG MRI Audio System, Resonance Technology inc.) were used to minimize the interference effect of scanner noise during fMRI [26].
