In a previous study, Iverson and colleagues reported a nonsignificant trend for athletes with three or more concussions to have worse preseason memory performance on ImPACT than those with no previous concussions (Cohen's d = .59, medium effect size), and recently concussed athletes with a history of multiple concussions had significantly greater decrements on the memory composite compared to concussed athletes with no injury history [ 34 ].
1
—
—