Fig. 1

Relationship between discrimination ability and odor identification threshold. a Method testing the discrimination ability to distinguish between 5 odor pairs by comparing three bottles and identifying the one with an odd stimulus. b Scatter plot of the relationship between discrimination ability (score) and identification threshold for rose odor in all 12 subjects. The dots represent the values of an individual subject. The double circles (◎) represents overlapping two dots. Spearman's correlation coefficient r with p value. c Comparison of discrimination ability (score) between two groups of different olfactory abilities, that is, low- and high-threshold groups (≤ 4 and ≥ 5, respectively). The horizontal lines and vertical bars show the mean and SEM values in each group. p = 0.03; the significant difference between the low- and high-threshold groups, tested by Mann–Whitney test