Flavor constitutes a complex multisensory phenomenon, with information from many different senses combining to create the overall experience of a particular food or beverage (see Verhagen & Engelen, 2006, for a review). Over the years, literally hundreds of published studies have examined the role of color, with mixed results (e.g., Clydesdale, 1993; Hoegg & Alba, 2007; Zampini, Sanabria, Phillips, & Spence, 2008). We applied a signal detection approach in order to determine once-and-for-all whether the influence of color was primarily perceptual or decisional in nature. Participants smelled strawberry-flavored, lemon-flavored, and unflavored solutions, with the intensity of the flavoring diluted such that the solutions were presented at near-threshold concentrations. Each solution was red, yellow, or clear in color, and each combination of flavor and color was presented equiprobably. In the detection task, participants had to detect the presence of a flavoring (i.e., present vs. absent). In the discrimination task, participants indicated which flavor, if any, they perceived (strawberry, lemon, or no flavour). In the detection task, color (whether congruent or incongruent) had no effect on either the sensitivity or the criterion of participants’ responses: that is, they did not make use of the color when judging whether a flavoring was present or not. Color also had no effect on the sensitivity of participants’ discrimination responses. However, there was a significant interaction between color and flavoring, such that color modulated the criteria used by participants in identifying which of the two flavorings was present. Specifically, when solutions were colored red, participants were more likely to indicate that they were strawberry-flavored and less likely to indicate that they were lemon-flavored, regardless of whether the solutions were actually strawberry or lemon flavored. This result suggests that the role of color in modulating flavor perception in humans is not perceptual, but occurs at a later (decisional) stage of information processing. These results help to make sense of the conflicting results reported in previous studies in this area.

References

Clydesdale, F. M. (1993). Color as a factor in food choice. Critical Reviews in Food Science and Nutrition, 33, 83-101.

Hoegg, J., & Alba, J. W. (2007). Taste perception: more than meets the tongue. Journal of Consumer Research, 33, 490-498.

Verhagen, J. V., & Engelen, L. (2006). The neurocognitive bases of human multimodal food perception: Sensory integration. Neuroscience and Biobehavioral Reviews, 30, 613-650.

Zampini, M., Wantling, E., Phillips, N., & Spence, C. (2008). Multisensory flavor perception: Assessing the influence of fruit acids and color cues on the perception of fruit-flavored beverages. Food Quality & Preference, 19, 335-343.