Detection of concealed information by P3 and frontal EEG asymmetry

► Frontal EEG asymmetry was calculated in the P3-based Concealed Information Test. ► Critical items elicited greater relative right frontal activity than non-critical items. ► Adding frontal EEG asymmetry to P3 amplitudes improved classification performance. ► Frontal EEG asymmetry can serve as a supplementary index in this test.