Volumetric studies were based on magnetic resonance images acquired on a Siemens Trio 3.0 Tesla scanner at the University of Utah. At time point 1, an 8-channel, receive-only RF head coil was used to acquire sagittal 3D MPRAGE T1-weighted images (inversion time=1100ms, echo time=2.93ms, repetition time=1800ms, flip angle=12degrees, field of view=56mm, slice thickness=1.0mm, 160 slices). No subjects in the current study underwent sedation for scanning. No complications were encountered in the scanning process. Additional neuroimaging details previously have been published (see Prigge et al., 2013a (link); 2013b ).