Eye deviation during rotation in darkness in trait anxiety: An early expression of perceptual avoidance?

Background: Patients with dizziness and patients with panic disorder and ag oraphobia share a common symptomatology. Numerous studies have investigated a potential link between anxiety and the vestibular system, but few of the m have addressed the specific topic of spatial representation. Methods: Passive whole-body rotations in the horizontal plane were imposed on two groups of subjects who differed in their level of trait anxiety. Sub jects were seated on a mobile robot in darkness. After each passive rotatio n, subjects were asked to reproduce the stimulus by driving the robot with a joystick and to perform a rotation of the same magnitude. Eye movements w ere recorded and analyzed. Results: No difference in either perception (accuracy in the reproduction t ask) or in VOR gain was found between the two groups of subjects. Mean eye deviation, caused by fast phases of the nystagmus, differed in the two grou ps. It was typically in the anticompensatory direction in the non-anxious g roup, and in the compensatory direction the anxious group. Such compensator y movement may be explained by an egocentric orientation strategy, that may in turn indicate a lack of interest toward the visual surroundings. Conclusions: An egocentric strategy for self-orientation exhibited at a lev el below the threshold of awareness could reveal the existence of a physiol ogical mode of processing leading to agoraphobic avoidance. (C) 2000 Societ y of Biological Psychiatry.