ELECTRICAL TASTE STIMULUS - CURRENT INTENSITY OR CURRENT-DENSITY

In electrical taste stimulation, current intensity is usually considered to be a simple equivalent of the taste stimulus intensity, this being analogous to the concentration of a chemical solution. However, there are indications that current density might be a better correlate of the true electrical taste stimulus. In the present study the relationship between the size of the stimulated human tongue area, the electrical current intensity, and the magnitude of elicited taste sensations was examined. Tests in six subjects showed that in order to achieve the standard sour taste magnitude when using electrode sizes that increased in size, the current intensity also had to be increased, but current density decreased. This might be attributed to spatial summation which is plausible only if current density was taken as a real electrical taste stimulus. Summation degree was less than complete, indicating that the density might be a predominant, but not the only factor in electrical stimulus efficacy. © 1990 Oxford University Press.