showed a trendp =.077
The Stroop effect (incongruent minus congruent) at electrode P4 showed a trend towards being slightly larger in substituted amphetamine users (|0.8| μV/m 2 ± 0.2) than in controls (|0.2| μV/m 2 ± 0.2) ( t (1 6 1) = 1.779; p =.077).