Scanning data were acquired with a 3-T Siemens Magnetom Trio MRI scanner (Siemens, Erlangen, Germany) fitted with a 12channel head-coil. An echo-planar imaging (EPI) sequence was applied for functional scans to obtain BOLD signal (echo time TE=30 ms, repeat time TR=70 ms, volume time 3.36 s) using 48 slices to cover the whole brain. The voxel resolution was 3 mm63 mm in-plane resolution, with a 2 mm slice thickness and 1 mm inter-slice gap. T1-weighted anatomical images were acquired at the end of experimental sessions for each subject (176 slices, resolution 16161 mm, TE=2.48 ms, TR=7.92 ms). We also recorded physiological responses, heart rate and breathing, for each subject.