A confusion matrix for the study of taste perception

Taste stimulus identification was studied in order to more thoroughly exami ne human taste perception. Ten replicates of an array of 10 taste stimuli-N aCl, KCl, Na glutamate, quinine.HCl, citric acid, sucrose, aspartame, and N aCl-sucrose, acid-sucrose, and quinine-sucrose mixtures-were presented to n ormal subjects for identification from a list of corresponding stimulus nam es. Because perceptually similar substances are confused in identification tasks, the result was a taste confusion matrix. Consistency of identificati on for the 10 stimuli (T-10) and for each stimulus pair (T-2) was quantifie d with measures derived from information theory Forty-two untrained subject s made an average of 57.4% correct identifications. An average T-10 of 2.25 of the maximum 3.32 bits and an average T-2 of 0.84 of a maximum 1.0 bit o f information were transmitted. In a second experiment, 40 trained subjects performed better than 20 untrained subjects. The results suggested that th e identification procedure may best be used to assess taste function follow ing 1-2 training replicates. The patterns of taste confusion indicate that the 10 stimuli resemble one another to varying extents, yet each can be con sidered perceptually unique.