Visual influence of shapes and semantic familiarity on human sweet sensitivity.

Vision influences taste. It is known that color plays an important role in flavor perception. However, the effect of other features of visual information such as shapes and semantic familiarity of words on the taste perception, particularly on taste sensitivity, is not clear yet. Here we study whether the sweet taste sensitivity of the subjects is affected by such visual inputs. By displaying basic geometric patterns or words with different degrees of semantic familiarity as visual inputs, the subjects rate the hedonic and semantic familiar scores, and taste a series of sucrose solutions, and their sweet sensitivities are accordingly analyzed. Our results show (1) shapes with curvature like circle and ellipse, with higher hedonic scores, increase the sweet sensitivity, whereas angular shapes like square, rectangle, triangle and pentagram do not affect sweet sensitivity; (2) semantic familiar words, with higher hedonic ratings as well, increase sweet sensitivity, whereas unfamiliar words do not affect or even reduce sweet sensitivities.