Learned color taste associations in a repeated brief exposure paradigm

Individuals can learn to associate tastes with odors through repeated exposure. We adapted this paradigm, testing whether individuals can learn to associate tastes with colors, and whether these learned color-taste associations generalize to unconditioned, but qualitatively similar stimuli. Experiment 1 tested if individuals could learn color-taste associations for prototypical tastes, while Experiment 2 tested if individuals could learn to discriminate specific bitter compounds using color-taste associations. Conditioned stimuli in Experiment 1 consisted of solutions representing four different prototypical taste qualities. Conditioned stimuli in Experiment 2 consisted of three different bitter stimuli and a sucrose control. Both experiments consisted of six laboratory visits. On day 1, participants rated intensities of conditioned and unconditioned stimuli. On days 2–5 participants completed triangle tests, where a color was systematically paired with high/low intensity combinations of the conditioned stimuli. On day 6, participants matched colorless solutions containing the conditioned and unconditioned stimuli to one of four colors in a forced choice task. In Experiment 1, group performance was significantly above chance (25%) when matching the conditioned taste stimulus to the previously paired color. Also, learning generalized to unconditioned stimuli with a similar taste quality. In Experiment 2, group performance versus chance (25%) indicated participants learned associated sweetness with the previously paired color, both for sucrose (conditioned stimulus) and aspartame (unconditioned stimulus). However, matching performance did not exceed chance for the three different bitterants. These data suggest that particular color-taste associations can be learned with repeated exposure, even when the exposure period is relatively brief.