Perception of slow pitch and roll body tilts in bilateral labyrinthine-defective subjects.

Lionel Bringoux (1) , Sébastien A. Schmerber (2) , Vincent Nougier (3) , Georges Dumas (2) , Pierre Alain Barraud (4) , Christian Raphel (4)

1 ISM - Institut des Sciences du Mouvement Etienne Jules Marey
2 Service d'ORL et de chirurgie cervicale
3 EA 597 - Laboratoire Sport et Performance Motrice
4 CRSSA - Centre de Recherches du Service de Santé des Armées

The aim of the present study was to examine whether the perception of slow body tilts in total darkness was affected by a complete loss of vestibular function. Four blindfolded bilateral labyrinthine-defective subjects (LDs) and 12 normal subjects (Normals) were seated and immobilized with large straps against the back of a rotating L-shaped platform, and were passively displaced from the upright at 0.05 degrees x s(-1) in the pitch and roll dimensions. Subjects were asked to detect the slow change in their body orientation, by indicating as soon as possible the direction of tilt. After a brief period of practice observed for all LDs at the beginning of the session, results showed no significant difference between LDs and Normals in the mean detection threshold recorded for each direction of tilt. The mean perceptual threshold was 4.4 versus 5.1 degrees in the roll dimension, and 6.1 versus 6.1 degrees in the pitch dimension, for the LDs and Normals, respectively. These findings indicate that the accurate perception of body orientation in quasi-static conditions is mainly allowed by somatosensory information rather than by otolithic inputs.

Domaines: Sciences cognitives

Lionel Bringoux, Sébastien A. Schmerber, Vincent Nougier, Georges Dumas, Pierre Alain Barraud, et al.. Perception of slow pitch and roll body tilts in bilateral labyrinthine-defective subjects.. Neuropsychologia, 2002, 40 (4), pp.367-72. ⟨hal-00193903⟩