REDUCED BINOCULAR DEPTH INVERSION IN PATIENTS WITH ALCOHOLISM

Binocular depth inversion represents an illusion of visual perception,serving to invert the perception of implausible hollow objects,e.g. a hollow face into a normal face. Such inversion occursfrequently, especially when objects with a higher degree offamiliarity (e.g. photographs of faces) are displayed. Cognitivefactors are assumed to override the binocular disparity cuesof stereopsis. The hypothesis was tested that during mild andmoderate alcohol withdrawal, and severe and mild alcohol intoxication,the central nervous system is unable to correct implausibleperceptual hypotheses. Measurements of binocular depth inversionin perception of three-dimensional objects were performed in10 patients with severe alcohol intoxication, in 10 subjectswith mild alcohol intoxication, in nine patients with moderatealcohol withdrawal treated with carbamazepine, in 10 patientswith moderate alcohol withdrawal without any pharmacologicaltreatment, in 11 patients with mild alcohol withdrawal and in10 healthy volunteers. The binocular depth inversion scoreswere highly elevated in the severely intoxicated patients groupand in the group with moderate withdrawal symptoms without carbamazepinetreatment, in comparison to the healthy volunteers. The datademonstrate a strong impairment of binocular depth inversionin moderate alcohol withdrawal and during severe alcohol intoxication.This supports the view that these states may be accompaniedby a disorganization of the interaction between sensory inputand top-down component. The effects of carbamazepine are discussed.