Do you like the sight or the feel of milk in coffee? Ecology and effortful attention in differential acuity and preference for sensed effects of milk substitute in vended coffee

A rapid method of discrimination scaling was used to measure individuals' acuity for levels of a complex stimulus perceived through several sensory modalities at once in a familiar context. The stimulus was a replacement for fresh milk used in vended coffee. The two experiments reported here compared the performance of ratings of the coffee's milkiness and creaminess when assessors were limited to the use of visual and/or olfactory cues. Better discrimination by milkiness ratings was observed during normal drinking and in a visual-only condition than when only oronasal or oral cues were available. Ratings relative to each assessor's ideal level of milkiness or creaminess showed diversity between assessor-preferred visual and oral characteristics of the milk substitute. However, instructing the assessor to attend to a particular aspect of the sample did not prevent the use of a better-discriminated characteristic if available to the senses. These results showed that the acceptability of a beverage or food depends more on the perceptible material than on efforts to direct attention to particular aspects.