Mean and standard deviation NAA/tCr and % Gray Matter (GM) data for the left/right pons (L1 –L6; R1 –R6) and cerebellum (C1 –C4) voxels selected from the CSI matrix for analysis.

Significant changes are underlined for the NAA/tCr ratio between controls and marked with ‘☆’ for low fatigue or ‘★’ for high fatigue voxels (p < 0.05). No significant differences were observed for NAA/tCr, or for %GM, in voxels in the pons (white) or in the cerebellum (light gray).