within-subjects (i.e., intraindividual) correlations with odor intensity not only for P2 source but also for N1 sink. Given that similar within-subjects correlations could not be obtained for odor thresholds and odor identification, it is plausible that an absence of significant between-subjects correlations for these measures with odor detection and CSD amplitudes in healthy controls is due to the same methodological limitation (i.e., lack of variability). In contrast, for CHR patients, who exhibited a greater variability in these measures, between-subjects correlations of odor identification and odor thresholds with odor detection and also P2 source were found in the expected direction (i.e., better nasal chemosensory performance, better odor detection, greater P2 source), which agrees with the correlational findings for P2 amplitude in a substantially larger (N = 95) and more heterogenous sample of healthy adults (Stuck et al., 2006). For these reasons, it seems prudent to interpret the intensity-dependent variations of N1 sink and P2 source amplitudes as direct, electrophysiologic correlates of odor perception, categorization and evaluation.
