Evoked Potentials Produced by Electric Stimulation on the Tongue

In a previous study [1], we reported that two kinds of responses were elicited by stimulation with a salt solution on the tongue, one being evoked by taste stimulation and the other resulting from the mechanical stimulus of the application of the solution. When a taste solution is used for stimulation, a lag time between the trigger and the stimulation may be unavoidable. Electrical stimulation, on the other hand, even with an artifact on evoked responses, demonstrates measurable and constant latency, and has a certain advantage as it can be readily applied with most signal processors that are available clinically. When electric stimulation is applied to the tongue, a metallic taste is induced together with the tactile sensation. Therefore, it may be assumed that not only the trigeminal nerve but also the chorda tympani is stimulated with electric stimulation applied to the anterior two-thirds of the tongue. In this study, we attempted to identify the component via the trigeminal nerve and via the chorda tympani.