Comparison of Subjective Responses to Semicircular Canal Stimulation Produced by Rotation About Different Axes

Abstract

A procedure has been developed for obtaining reliable measures of sensation associated with semicircular canal stimulation. Theoretically these measures can be used along with measures of nystagmiis to estimate several vestibular response system parameters. In this experiment, responses produced by stimulation of the horizontal semicircular canals are compared with those produced by stimulation of the vertical canals. Group mean estimates of subjective angular displacement obtained from forty US Navy flight students were approximately accurate for stimulation of both horizontal and vertical canals. Significant individual differences were found within the group. From the responses obtained, mean estimates of vestibular system parameters were calculated. The method appears to be a practical means of measuring the K. (θ/Δ) parameter which has not been assessed in the past due to lack of a suitable method.