reduction of GBRs to target (Haig et al., 2000b; Symond et al., 2005) and non-target (Haig et al., 2000b; Hall et al., 2011b; Roach and Mathalon, 2008) auditory tones, suggesting that the early-evoked GBRs to auditory stimuli are either compromised by a lack of phase consistency across trials, reduced response magnitude, or some combination of the two. While gamma oscillation abnormalities are evident in chronic schizophrenia patients (Gallinat et al., 2004; Hall et al., 2011a; Hall et al., 2011b; Kwon et al., 1999; Light et al., 2006; e.g., Roach and Mathalon, 2008; Roach, this issue), in first-episode psychosis (Spencer et al., 2008b; Symond et al., 2005; Williams et al., 2009), and to a lesser degree, in unaffected relatives (Hall et al., 2011b; Hong et al., 2004b; Leicht et al., 2010a), but see (Hall et al., 2011a), it remains unclear whether they are present in individuals at clinical high risk for the development of psychosis.
