Memory psychophysics for chemosensation: perceptual and mental mixtures of odor and taste

Subjects made quantitative judgements of the overall intensity of odor-taste mixtures, which were either presented physically (perceptual estimation) or represented symbolically by pairs of colors that referred to their unmixed constituents (memory-based estimation). In the latter condition, the mixtures were constructed subjectively by mixing mentally the remembered representations of the odor and taste components. Despite the great phenomenal difference between the two conditions, the pattern of results was largely the same for perceived and for mental mixtures. The rule of odor-taste integration was approximately additive in both cases. The invariance of this rule is particularly impressive given that all of the stimuli were presented intraorally, so that the odorants were mislocalized at the mouth. The findings imply an important role for cognition in chemosensation.