In both studies (Jones et al., 2006; Rangaswamy et al., 2007), ERP amplitude measures and ERO measures in different sub-bands across delta, theta and alpha frequency bands were extracted from the event-related data. Two types of ERO measures were quantified: (i) evoked ERO power measures were computed by applying time-frequency analysis directly to the trial-averaged ERP waveforms and (ii) total ERO power measures were calculated by applying time-frequency analysis to each individual trial and averaging the results across trials. Total ERO power contains contributions from both phase-locked and non-phase-locked activity, while evoked ERO power quantifies phase-locked activity only. Multivariate analysis of variance (MANOVA) was applied to the ERP and ERO measures to investigate which measures best discriminated the groups. The principle finding was that in addition to the P3b amplitude, the δ evoked power and the θ total power significantly distinguished the two groups from one another. Both studies concluded that the ERO power measures provided unique information beyond that of the ERP measures for group discrimination. While there was agreement between the two studies that ERO measures discriminated the
