In addition to obtaining standardized measures of odor detection thresholds and odor identification (Kobal et al., 2000), odor detection sensitivity was measured during the olfactory ERP paradigm to estimate the extent to which the parametric manipulation of odor intensity reflects a co-variation of the ability to detect odors and their electrophysiologic correlates. Given that the abnormal olfactory ERPs in family members were associated with odor identification, a predictor for development of schizophrenia in CHR patients (Brewer et al., 2003), a secondary focus was whether electrophysiologic, behavioral and nasal chemosensory performance measures of olfactory function in CHR patients may improve prediction of transition to schizophrenia. Finally, it was hypothesized that deficits in olfactory function would be associated with severity of negative symptoms (Brewer et al., 2001; Corcoran et al., 2005; Good et al., 2006; Malaspina & Coleman, 2003; Moberg et al., 2006).
