Electrical Generation of Intranasal Irritating Chemosensation

Percutaneous electrical stimulation modifies brain and nerve excitability and also stimulates various sensory organs. Although it can be applied to sensory information displays, virtual reality, and human augmentation, the effect on human intranasal chemosensation, including olfaction, is not clearly understood. In this paper, we introduce galvanic olfactory stimulation, in which non-invasive electrical stimulation induces virtual intranasal chemosensation. For this purpose, we designed an electrode configuration using a finite element analysis simulation. We then conducted two psychophysical experiments comparing different stimulation configurations and asking subjects to describe their sensation experiences. The results demonstrate that galvanic olfactory stimulation using a pair of electrodes at the nasal bridge and the dorsal surface of the neck induces virtual irritating intranasal chemosensation. This observation suggests that, at the very least, the proposed galvanic olfactory stimulation method induces irritating intranasal chemosensation. This implies that an electric current stimulates the trigeminal nerve in the inner region of the nasal cavity. To the best of our knowledge, this is the first report to demonstrate virtual intranasal chemosensation using non-invasive electrical stimulation of the external surface of the nose.