Local Normalization

Based on these initial findings, and on the radiographic subtlety and variability FCDs, we suspected that the features of FCDs overlapped significantly with those found in normal cortex.  To assess whether FCD lesions in MRI+ patients were global outliers in our feature space, we compared the average Mahalanobis distances of 1000 randomly selected patches from 1) normal HV cortex, 2) insular and motor cortex outlier ROIs, and 3) FCD lesion masks.  For each comparison, the mean and standard deviation of the included patches are reported.  Welch's t-test was used to compare the distribution of distances and cosine similarities between patches, as they were approximately normally distributed but often had unequal variances.  Effect size was reported as in \cite{cohen1988statistical}\(d=0.2\) as small\(d=0.5\) as medium, and \(d=0.5\) as large.