Figure 6.

(A) Factor loadings of the first three PCA factors (with explained variance) extracted from olfactory CSD waveforms (N = 41). (B) CSD factor score topographies corresponding to N1 sink (top) and P2 source (bottom) for 21 CHR patients and 20 healthy controls comparing H₂S stimuli of weak, medium, and strong intensity and blank air. (C) Squared univariate (channel-specific) paired samples T statistics thresholded at the 95^th quantile (p = 0.05) of the corresponding randomization distribution (maximum of all 49-channel squared univariate paired samples T statistics) of difference between H₂S stimuli (pooled across intensity) and blank air (N = 41). To facilitate comparisons of the max(T²) topographies with the underlying sink-source difference topographies, the sign of the difference at each site was applied to the respective T² value, which is otherwise always positive. Inset topographies show the sites selected for repeated measures ANOVA models performed on CSD factors 345 (N1 sink) and 600 (P2 source) to probe region-specific sink (cyan) or source (orange) activations associated with odor detection, as indicated by colored locations. All topographies are two-dimensional representations of spherical spline interpolations (m = 2; λ = 0) derived from the mean factors scores or T² statistics available for each recording site.