The method of silent substitution for examining melanopsin contributions to pupil control
- 1University of Oxford, United Kingdom
- 2University of Groningen, Netherlands
The human pupillary light response is driven by all classes of photoreceptors in the human eye — the three classes of cones, the rods, and the intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing the photopigment melanopsin. These photoreceptor classes have distinct but overlapping spectral tuning, and even a monochromatic light with a wavelength matched to the peak spectral sensitivity of a given photoreceptor will stimulate all photoreceptors. The method of silent substitution uses pairs of lights to selectively stimulate a given class of photoreceptors while keeping the activation of all others constant. In this primer, we describe the method of silent substitution and provide an overview of studies that have used it to examine inputs to the human pupillary light response.
Keywords: Pupil, Melanopsin, Silent substitution, Colour vision, Pupillometry, ipRGC (intrinsically photosensitive retinal ganglion cell)
Received: 04 Sep 2018;
Accepted: 17 Oct 2018.
Edited by:Andrew J. Zele, Queensland University of Technology, Australia
Reviewed by:Dingcai Cao, University of Illinois at Chicago, United States
Sei-ichi Tsujimura, Kagoshima University, Japan
Copyright: © 2018 Spitschan and Woelders. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Manuel Spitschan, University of Oxford, Oxford, United Kingdom, email@example.com