The mixed-model ANOVA analysis of P50 amplitude showed a trend toward a significant main effect of group ( F (1,25) = 3.58, p = 0.07) but no significant main effects of stimulus type or attention as well as no significant interactions between any of the factors ( Figure 2B ).
There was also a trend toward a significant effect of stimulus type in the group with a history of concussion ( F (1,39) = 3.33, p = 0.08) but not in the control group; since it did not reach statistical significance in either group, the main effect of stimulus type which was shown in the mixed-model ANOVA was not considered further ( Figure 2B ).