The monotonic increase of N1 sink and P2 source with increased concentrations of H2S is in close agreement with previous findings (Huart et al., 2012; Stuck et al., 2006; Turetsky et al., 2003a; Wang et al., 2002). Furthermore, the present findings demonstrate that the intensity-dependent amplitudes of N1 sink and P2 source were closely related to the individual ability to correctly detect H2S stimuli, revealing almost 80% common variance between increases in odor detection sensitivity and N1 sink in healthy controls. Notably, this robust relationship may be weakened or entirely obscured in betweensubjects correlations because of a lack of interindividual variability. Although prior studies reported between-subjects correlations between nasal chemosensory performance and olfactory P2 amplitude (Stuck et al., 2006) or an olfactory time-frequency theta component overlapping a late P2 time interval (Huart et al., 2012), the present findings reveal robust 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
