Fig. 1.

Normalization of OB odor-response patterns. (A) Raw glomerular activity maps in response to presentation of 2-hexanone at three vapor-phase concentrations. (B) A z score normalization of these activity maps results in a representation that depends less on concentration. (C) Combined data from four odorants (2-hexanone, methyl valerate, n-pentanal, and n-pentanol) illustrating the reduction in pattern dissimilarity across concentrations produced by normalization. Dissimilarity indices between glomerular activity maps of the same odorant presented at different concentrations were reduced for all pairs of concentrations and all odorants tested after z score normalization. (D) The proportional reduction in pattern dissimilarity across all pairs of concentrations and odorants. (E) Proportional changes in pattern dissimilarity between odorant pairs presented at the same concentration, averaged across all pairwise comparisons.