Figure 1.
Hedonic scores (mean and SEM values) related to each taste, from −5 = (the most unpleasant) to +5 ( = the most pleasant).
Each taste was compared to water by multiple comparisons (Bonferroni's post-hoc test). *P<0.05. W, water; S, sweet; C, citric acid; N, NaCl; M, monosodium glutamate; Q, quinine; l, low concentration; m, medium concentration; h, high concentration.
Figure 2.
Changes in facial skin blood-flow distribution in a subject before (Pre) and during (Stimulus) gustatory stimulation.
The colored bar on the right side indicates the blood flow magnitude, with the red and blue colors indicating higher and lower blood flows, respectively. The white ellipses in the six facial regions represent the target areas where blood flow was measured. Sweet (a) and umami (b) stimuli characteristically increased eyelid skin blood flow, while bitter (c) stimuli decreased nose skin blood flow.
Figure 3.
Sweet, umami, and bitter stimuli were significantly correlated with hedonic rating and blood flow in specific facial skin regions.
Sweet (a) and umami (b) stimuli were significantly correlated with hedonic rating and eyelid skin blood flow (sweet: r = 0.60, n = 41; umami: r = 0.57, n = 44). Bitter (c) stimuli were significantly correlated with hedonic rating and nose skin blood flow (r = 0.52, n = 38).
Table 1.
Changes in mean facial skin blood flow in response to various taste stimuli.
Table 2.
The tested concentrations for each taste substance.