fMRI image acquisition and data analysis
Images were acquired using a 3T Siemens TrioTim MRI scanner (Siemens, Erlangen, Germany). Because participants wore pneumatic headphones, we used a 12- instead of a 32-channel headcoil as the latter was too small to fit participants’ heads with headphones. Using a 12-channel headcoil does not significantly decrease blood-oxygen-level-dependent (BOLD) signal in cortical areasFunctional images were acquired using a T2*-weighted echo-planar imaging sequence (echo time (TE) = 30 ms, repetition time (TR) = 2500 ms, flip angle = 90°, voxel-size = 2 × 2 × 3 mm, slice thickness = 3mm, field of view (FOV) = 192 mm, 37 slices). For purposes of normalization, a T1-weighted structural scan was acquired (TE = 2.54 ms, TR = 1660 ms, inversion time = 800 ms, slice thickness = 0.8 mm, matrix size = 320 × 320, FOV = 256 mm, flip angle = 9°, voxel-size = 0.8 × 0.8 × 0.8 mm, 208 sagittal slices).First, fMRI images were checked manually for abnormalities upon which three participants had to be excluded due to artifacts in functional images. Functional EPI images were analyzed using SPM12 (Wellcome Center for Neuroimaging, London, UK, 