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) Inhibitors,research,lifescience,medical 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. Studies using healthy, nonclinical participants have shown that stronger theta ERS is associated with Selleckchem JNK inhibitor increased memory load and allocation of attention to task demands (Klimesch 1996; Burgess and Inhibitors,research,lifescience,medical Gruzelier 1997; Doppelmayr et al. 2000; McEvoy et al. 2001; Missonnier et al. 2006; Deiber et al. 2007). While these cognitive processes have been shown to be affected by alcohol use/abuse (Nixon and Glenn 1995; Ratti et al. 1999; Beatty et al. 2000; Schmidt
et al. 2005), aspects of these processes have also been shown to at least Inhibitors,research,lifescience,medical partially resolve after long-term abstinence from alcohol (Fein and McGillivray 2007; Fein et al. 2010). Greater theta ERS in LTAA suggests that LTAA may need to engage working memory and attentional processes Inhibitors,research,lifescience,medical more strongly than do control
participants in order to successfully perform the target detection task. The difference in brain activity, indexed by larger theta ERS in LTAA compared with controls, suggests that increased theta ERS may be a biomarker for a morbid effect of alcohol abuse on brain function. While we have shown the theta ERS effect in two independent groups of LTAA, Inhibitors,research,lifescience,medical this does not establish that the effect reflects a morbid effect of alcoholism on brain function that at least partially persists into long-term abstinence. The present study compared evoked and induced theta activity in a group of alcoholics who just recently initiated abstinence from alcohol (between 6- and 15-week Phosphatidylinositol diacylglycerol-lyase abstinent; referred to as short-term abstinent alcoholics, STAA) to the LTAA (>18-month abstinent) and nonalcoholic control (NAC) groups from Gilmore and Fein (2012). If the magnitude of the theta ERS decreases as a function of length of abstinence with no other concomitant differences between groups (e.g., in severity of alcohol use or in family history density of alcohol problems), it would lend more evidence to the assertion that increased theta ERS is a biomarker for an effect of alcohol use/abuse on the brain, and that this effect at least partially resolves with extended abstinence.