fMRI scan geometry and definition of parameters.

(A) fMRI scan geometry overlaid on a sagittal scout image acquired at the midline of the brain. The four 1.0 mm thick scan slices, indicated by parallel solid lines and labeled 1 to 4, are oriented orthogonal to the sagittal plane as shown. The interslice gap is 0.2 mm. The location of the SC at midline is indicated. The anterior, posterior, dorsal, and ventral sides of the brain are also indicated. (B) Representative BOLD signal with maximum response amplitude (PEAK) normalized to 1. The times to rise to 50% of PEAK (t50) and to return to 50% of PEAK (t150) are defined. The areas under the rising (rAUS) and falling (fAUS) portions of the signal are defined by the areas shaded in blue and red, respectively. The green bar indicates the 1 s stimulation period.