FIGURE 3.

Correlations of finger tapping speed with surface morphology and volume preserved warping (VPW). The main effect of a diagnosis of Tourette syndrome (TS) on surface morphology and VPW is presented in the top row for comparison (see Fig 1). The statistical model for the correlation of finger tapping speed with surface morphology was assessed in 69 control subjects and 96 TS subjects for whom this measure was available. Analysis for the control group included covariates for age, sex, and the age-by-sex interaction. Analysis for the TS group included covariates for ADHD, OCD, age, sex, and the age-by-sex interaction. The color bar indicates the color coding for p values associated with the effect of finger tapping speed, with warmer colors (red and yellow) indicating protruding surfaces in surface morphology images or local volume expansion with improved finger tapping performance, whereas cooler colors (purple and blue) indicate indented surfaces in surface morphology images or local volume contraction with greater finger tapping speed. These images are not Gaussian random field-corrected. Increasing performance of right finger tapping accompanies progressively more prominent volume reductions of the right lateral cerebellar hemisphere and less substantial volume reduction of the left lateral cerebellar hemisphere in both control and TS participants. This finding localizes to right crus (Cr) I and lobule VI, overlapping anatomic regions where a local volume reduction is present in those with a diagnosis of TS.