The main purpose of testing taste is to look for evidence of dysfunction of the sensory fibers of the facial (seventh) cranial nerve that convey taste from the anterior tongue.

Taste needs only to be tested in patients suspected of having peripheral (lower motor neuron) facial weakness or in any patient with a complaint of diminished taste.

Taste from the anterior two-thirds of the tongue is conveyed by the chorda tympani nerve, which joins the seventh nerve and sends taste sensation to the medulla.

Sugar, water, a paper cup, and a tongue depressor (or a cotton swab).