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Optimizing methods to isolate melanopsin-directed responses.
- Source :
-
Journal of the Optical Society of America. A, Optics, image science, and vision [J Opt Soc Am A Opt Image Sci Vis] 2021 Jul 01; Vol. 38 (7), pp. 1051-1064. - Publication Year :
- 2021
-
Abstract
- The intrinsic melanopsin photoresponse may initiate visual signals that differ in spatiotemporal characteristics from the cone-opsin- and rhodopsin-mediated signals. Applying the CIE standard observer functions in silent-substitution methods can require individual differences in photoreceptor spectral sensitivities and pre-receptoral filtering to be corrected; failure to do so can lead to the intrusion of more sensitive cone processes with putative melanopsin-directed stimuli. Here we evaluate heterochromatic flicker photometry (HFP) and photoreceptor-directed temporal white noise as techniques to limit the effect of these individual differences. Individualized luminous efficiency functions ( V ( λ )) were compared to the CIE standard observer functions. We show that adapting chromaticities used in silent-substitution methods can deviate by up to 54% in luminance when estimated with the individual and standard observer functions. These deviations lead to inadvertent cone intrusions in the visual functions measured with melanopsin-directed stimuli. To eliminate the intrusions, individual HFP corrections are sufficient at low frequencies (∼1 H z ) but temporal white noise is also required at higher frequencies to desensitize penumbral cones. We therefore recommend the selective application of individualized observer calibration and/or temporal white noise in silent-substitution paradigms when studying melanopsin-directed photoresponses.
Details
- Language :
- English
- ISSN :
- 1520-8532
- Volume :
- 38
- Issue :
- 7
- Database :
- MEDLINE
- Journal :
- Journal of the Optical Society of America. A, Optics, image science, and vision
- Publication Type :
- Academic Journal
- Accession number :
- 34263761
- Full Text :
- https://doi.org/10.1364/JOSAA.423343