Monocular and Binocular Perception of Verticality and the Relationship of Ocular Dominance

Abstract

Certain organismic states may be altered through experimental manipulation of such factors as body-tilt (supported or unsupported), sidewise head-tilt, body-rotation, or electrical or mechanical stimulation of the neck muscles.1 It has been suggested that these manipulations, which induce concurrent asymmetrical responses in the proprioceptive, tactile, and vestibular feedback mechanisms, contribute to error in the perception of verticality,2 and it is with this induced asymmetry that most investigators have concerned themselves. Little consideration has been given to an analysis of the possible relationship which may exist between natural bilateral asymmetry and the perception of verticality. Walls has described in great detail the nature of bilateral asymmetry in the visual system.3 He clearly distinguishes between two types of ocular dominance; rivalry-dominance, which is purely sensory, and sighting dominance, which is motor in character. The relationship between visual asymmetry and the perception of verticality has yet to be described. The present investigation represents an attempt to describe the relationship between the left-eye, right-eye, and binocular perception of the vertical, and the possible involvement of ocular dominance.