NEW DIAGNOSTIC-TESTS FOR THE FUNCTION OF UTRICLES, SACCULES AND SOMATIC GRAVICEPTORS

Clinical tests that allow us to discriminate between utricular, saccul ar and somatic effects on gravity perception and control are desirable but wanting. A new test battery is presented which combines four expe rimental paradigms based on the subjective horizontal body position (S HP), namely, a test on a tiltable board and on a sled centrifuge under varied leg position, with two paradigms based on the subjective visua l vertical (SVV). It is shown by a combination of experiments and dedu ctions, that, why, and how these tests can separate the effects of oto liths from those of somatic graviceptors, the effects of the utricles from those of the saccules, and the effects of the constituents of the somatic graviception from each other. The present study demonstrates the capabilities of the tests as well as their limitations.