FIG 1. Average performance scores (percentages) for concussed players do not change between baseline (white) and postconcussion (dark gray) sessions. Similarly, no change was observed for the control players when we compared the first baseline session (light gray) with the second baseline session (black). Performance on the digit span and addition tasks were similar and consistently above 80% correct for all sessions. The subtraction task appeared considerably more difficult with percentages of correct values well below those for the other tasks.