These theta ERS findings in LTAA represent a novel and intriguing extension of the analysis of electrophysiological data recorded during simple visual target detection tasks that have previously shown differences in the average response to target stimuli between control participants and alcoholics (as well as those with other externalizing spectrum disorders; see, e.g., Porjesz et al. 2005 for a review). In examining induced theta ERS, Fein and colleagues (Andrew and Fein 2010b; Gilmore and Fein 2012) analyzed the part of the data that was considered noise in previous work: the non-stimulus-phase-locked EEG data that is typically averaged out while extracting the phase-locked, or evoked, event-related potentials and oscillations (ERPs and EROs, respectively). Furthermore, Fein and colleagues (Andrew and Fein 2010b; Gilmore and Fein 2012) found that greater theta ERS in alcoholics is independent of and opposite in direction to the classic finding of lower amplitude P3b (and lower evoked theta power) in alcoholics (e.g., Begleiter et al. 1984; Iacono et al. 2003; Fein and Chang 2006; Jones et al. 2006; Rangaswamy et al. 2007). In other words, the theta ERS effect is dissociable from the endophenotypic effects associated with the evoked measures.
