  Numerous studies have been conducted on display techniques for intranasal
chemosensory perception. However, a limited number of studies have focused on
the presentation of sensory spatial information. To artificially produce
intranasal chemosensory spatial perception, we focused on a technique to induce
intranasal chemosensation by transcutaneous electrical stimulation between the
nasal bridge and the back of the neck. Whether this technique stimulates the
trigeminal nerve or the olfactory nerve remains debatable; if this method
stimulates the trigeminal nerve, the differences in the amount of stimulation
to the left and right trigeminal branches would evoke lateralization of
intranasal chemosensory perception. Therefore, we propose a novel method to
lateralize intranasal chemosensation by selectively stimulating the left or
right trigeminal nerve branches through the shifting of an electrode on the
nasal bridge to the left or right. Finite element simulations reveal that
electrical stimulation applied between the electrodes on the left/right nasal
bridge and the back of the neck results in the construction of a high current
density area on the left/right branch of the trigeminal nerve. The results of
two psychophysical experiments reveal that intranasal chemosensation can be
lateralized by using the proposed method. The results of our experiment also
suggest that lateralization is not the result of electrically induced tactile
sensation of the skin surface but rather due to the distribution of stimuli to
the trigeminal nerves. To the best of our knowledge, this study is the first
successful lateralization of intranasal chemosensation that utilizes an
easy-to-apply method without involving nostril blocking.
