Among the clinical variables considered for patients, severity of negative symptoms was correlated with reduced P2 source (r = −0.52, p = 0.007) and reduced N1 sink, but this was significant only for the right (r = 0.41, p = 0.03) but not left hemisphere (r = 0.23, p = 0.16). Severity of negative symptoms was also correlated with poorer odor identification (r = −0.37, p = 0.05), and right (r = −0.44, p = 0.02) but not left (r = −0.14, p = 0.27) odor thresholds. However, neither of the correlations between negative symptoms and N1 sink or odor thresholds differed between the left and right hemisphere or nostril (both z < 0.98, both p > 0.16). Finally, lower global assessment of function score on SIPS was associated with poorer odor detection ( r = 0.44, p = 0.02) and reduced right (r = −0.64, p < 0.001) but not left (r = −0.29, p = 0.10) N1 sink, which attained a marginal significant difference between hemispheres (z = 1.37, p = 0.08).
