ERPs in schizophrenia (Kayser et al., 2010; Turetsky et al., 2003a), the preserved olfactory ERPs in CHR patients may indicate that olfactory ERP abnormalities do not emerge before disease onset, thereby implicating a state rather than a trait measures. However, such an interpretation would be at odds with evidence of reduced olfactory ERPs in first-degree relatives of schizophrenia patients (Turetsky et al., 2008), and also with the present observations that olfactory ERPs were markedly reduced in the three patients who later developed psychosis. Rather, compared to healthy controls, CHR patients had individually a less robust association between odor intensity, odor detection, and olfactory ERPs, suggesting either a less coherent interplay of different elements and functions within the olfactory system, or a greater variability in olfactory processing among CHR patients, or both. An intriguing consideration is whether the sequence of olfactory ERPs reflects different stages of conscious odor processing, thereby providing insight into odor perception preceding smell awareness and its correct detection, but this is admittedly speculative. Thus, despite the lack of overall group differences in olfactory function, the present findings provide strong evidence for the hypothesis that certain aspects of olfactory function are impaired in at least a subgroup of
