Photopic Rapid Adaptation in the Electroretinogram: a White Noise Analysis

Author: Larkin, Ross Martin

Year: 1979

Degree: Dissertation (Ph.D.)

Advisor: Fender, Derek H.

Committee Member: Unknown, Unknown

Option: Engineering

DOI: 10.7907/0s8a-v524

Abstract

When light enters the eye it initiates a complicated chain of events which eventually lead to the sensation of vision. The electroretinogram (ERG) is a widely used indirect measure of the visual system, One of the most interesting aspects of the visual system, adaptation, is its ability to function over a very wide range of incoming light intensities, This thesis is concerned with the study of the retina during small, fast changes in the state of adaptation.

To study rapid adaptation, a new technique was developed which may also be used for looking at other biological systems, Kernels (a form of cross-correlation), when used with white noise stimuli, have proven very useful in the study of the dynamics of photopic rapid adaptation, Using first order kernels we have probed the wide range of adaptation and compared kernels to flash responses, With the second order kernel we found evidence that a late (125 ms) wave in the ERG is caused by rapid adaptation, identified the components of highly abnormal ERG 1s and obtained basic information about the internal organization of a system. The third order kernel characterized suppression-recovery in the photopic ERG.

We then speculated on the correlation of our results with some of the prevailing views of the organization and operation of rapid adaptation in the photoreceptors of the retina,

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