The scan protocol will include both an anatomical T1-weighted structural MPRAGE scan with spatial resolution 1x1x1mm3 that will be used to guide the TMS testing in Aim 2 and DTI which will allow investigation of the variation in connectivity of the CST in these infants with perinatal stroke. High angular resolution diffusion imaging (HARDI) with whole-brain coverage using the 'Human Connectome Project' (HCP) DTI sequence and spatial resolution 1.8x1.8x1.8mm3, b-value=1500 s/mm2, 128 gradient directions and 15 additional nondiffusion weighted images will be obtained. HCP tractographic methods will be applied to the HARDI data to define the two CST's and compute the integrity metrics of track volume and mean fractional anisotropy (FA). The complete MRI dataset will be obtained in less than 38 minutes.