The Journal of Neurophysiology Vol. 81 No. 2 February 1999, pp. 945-949
Copyright ©1999 The American Physiological Society

Short-Latency Vergence Eye Movements Induced by Radial Optic Flow in Humans: Dependence on Ambient Vergence Level

D.-S. Yang, E. J. Fitzgibbon, and F. A. Miles

Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892

Yang, D.-S., E. J. Fitzgibbon, and F. A. Miles. Short-latency vergence eye movements induced by radial optic flow in humans: dependence on ambient vergence level. J. Neurophysiol. 81: 945-949, 1999. Radial patterns of optic flow, such as those experienced by moving observers who look in the direction of heading, evoke vergence eye movements at short latency. We have investigated the dependence of these responses on the ambient vergence level. Human subjects faced a large tangent screen onto which two identical random-dot patterns were back-projected. A system of crossed polarizers ensured that each eye saw only one of the patterns, with mirror galvanometers to control the horizontal positions of the images and hence the vergence angle between the two eyes. After converging the subject's eyes at one of several distances ranging from 16.7 cm to infinity, both patterns were replaced with new ones (using a system of shutters and two additional projectors) so as to simulate the radial flow associated with a sudden 4% change in viewing distance with the focus of expansion/contraction imaged in or very near both foveas. Radial-flow steps induced transient vergence at latencies of 80-100 ms, expansions causing increases in convergence and contractions the converse. Based on the change in vergence 90-140 ms after the onset of the steps, responses were proportional to the preexisting vergence angle (and hence would be expected to be inversely proportional to viewing distance under normal conditions). We suggest that this property assists the observer who wants to fixate ahead while passing through a visually cluttered area (e.g., a forest) and so wants to avoid making vergence responses to the optic flow created by the nearby objects in the periphery.

This article has been cited by other articles:

				K. Miura, Y. Sugita, K. Matsuura, N. Inaba, K. Kawano, and F. A. Miles The Initial Disparity Vergence Elicited With Single and Dual Grating Stimuli in Monkeys: Evidence for Disparity Energy Sensing and Nonlinear Interactions J Neurophysiol, November 1, 2008; 100(5): 2907 - 2918. [Abstract] [Full Text] [PDF]

				A. Takemura, Y. Murata, K. Kawano, and F. A. Miles Deficits in Short-Latency Tracking Eye Movements after Chemical Lesions in Monkey Cortical Areas MT and MST J. Neurosci., January 17, 2007; 27(3): 529 - 541. [Abstract] [Full Text] [PDF]

				M. Wei and D. E. Angelaki Foveal Visual Strategy during Self-Motion Is Independent of Spatial Attention J. Neurosci., January 11, 2006; 26(2): 564 - 572. [Abstract] [Full Text] [PDF]

				B. Adeyemo and D. E. Angelaki Similar Kinematic Properties for Ocular Following and Smooth Pursuit Eye Movements J Neurophysiol, March 1, 2005; 93(3): 1710 - 1717. [Abstract] [Full Text] [PDF]

				D. E. Angelaki Eyes on Target: What Neurons Must do for the Vestibuloocular Reflex During Linear Motion J Neurophysiol, July 1, 2004; 92(1): 20 - 35. [Abstract] [Full Text] [PDF]

				B. J. M. Hess and D. E. Angelaki Vestibular Contributions to Gaze Stability During Transient Forward and Backward Motion J Neurophysiol, September 1, 2003; 90(3): 1996 - 2004. [Abstract] [Full Text] [PDF]

				H.-H. Zhou, M. Wei, and D. E. Angelaki Motor Scaling By Viewing Distance of Early Visual Motion Signals During Smooth Pursuit J Neurophysiol, November 1, 2002; 88(5): 2880 - 2885. [Abstract] [Full Text] [PDF]

				M. Q. McHenry and D. E. Angelaki Primate Translational Vestibuloocular Reflexes. II. Version and Vergence Responses to Fore-Aft Motion J Neurophysiol, March 1, 2000; 83(3): 1648 - 1661. [Abstract] [Full Text] [PDF]