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2015 Charles F. Prentice Medal Award Lecture: Neural Organization of Binocular Vision

Freeman, Ralph D. OD, PhD*

doi: 10.1097/OPX.0000000000001116
Feature Articles – Public Access

ABSTRACT During a Research Career Development Award from the National Eye Institute, I spent a year at the University of Cambridge doing research with John Robson. The goal was to use a visual stimulation approach that had not been previously attempted, with the intention of exploring fundamental organization principles of the neural basis of binocular vision. The idea was to use sinusoidal gratings that drifted before both eyes such that the relative phase for one eye was fixed while that of the other was varied. This provided binocular stimuli of variable relative phase, i.e. retinal disparity, to enable testing of binocular response characteristics. We were able to obtain different types of disparity tuning functions for neurons in the primary visual cortex. This work, followed by extended investigations in Berkeley, provided basic information regarding response characteristics of simple and complex cells. We have also shown for monocular deprivation, an approximate model for human amblyopia, that many neurons remain connected to the deprived eye, as demonstrated with dichoptic activation. A selected portion of this work is described here.

University of California, Berkeley School of Optometry, Berkeley, CA *

Submitted: February 2, 2017

Accepted: May 16, 2017

Funding/Support: National Institutes of Health (NIH) EY01175.

Conflict of Interest Disclosure: The author has not reported a conflict of interest.

Author Contributions and Acknowledgments: Conceptualization: RF; Investigation: RF; Project Administration: RF; Supervision: RF.

I am enormously grateful for the continual support of the National Eye Institute during the entire course of my career. Clearly, the work we have undertaken and completed could not have been done without this support. I am also indebted to students, collaborators, and colleagues for their crucial contributions, helpful exchanges, and critical discussions, which have resulted in what we were able to achieve. Although many individuals should be acknowledged, particular thanks are extended to the following people who were directly or indirectly involved in the work described here. Horace Barlow has been a primary mentor. Jack Pettigrew taught me a great deal about neurophysiology and mountain climbing. John Robson collaborated on the initial work reported here and has been a career-long colleague. Izumi Ohzawa was a graduate student and then worked with me for more than 20 years. Those years were by far the most productive of my career. His contributions were essential for all aspects of our research and his contributions were beyond exceptional. Aki Anzai and Greg DeAngelis made significant contributions to the neurophysiological investigations of binocular vision. To these individuals and the many others who joined and contributed to our efforts, I am deeply grateful.

© 2017 American Academy of Optometry