Functional MRI acquisition

The BOLD fMRI measurements were obtained in a whole-body 3 T Magnetom Trio scanner, with 12 channels (Siemens). The fMRI protocols were based on multi-slice gradient echoplanar imaging (EPI) and a standard head coil. The functional data were collected under the following timing parameters: time to repetition (TR) = 1.5 s, time to echo (TE) = 30 ms, FA = 70°, imaging matrix = 80 × 80, field of view (FOV) = 24 × 24 cm (i.e., in-plane resolution of 3 mm). We used a relatively short TR value to later superimpose the phase-locking spectral analysis approach. Twenty six slices with slice thickness = 4.5 mm and no gaps were oriented in the axial position for complete coverage of the cortex.