The significant group × stimulus interaction effect (F(10,85) = 2.669; p = 0.007) accounts for 23.9% of the variance. Separate between-subjects one-way MANOVAs for each level of stimulus were used to further investigate this interaction effect (Table 2 shows the one-way MANOVA results for the reference θ power for the target stimulus). The results show that the induced θ power for the target stimulus significantly discriminates the groups, with the LTAAs showing a larger ERS than the NACs. The effect is largest at frontal electrode sites. The induced θ power for the non-target stimuli (rare and standard) do not significantly discriminate the groups.
