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Electroretinograms in S‐cone monochromacy using S‐cone and rod isolating stimuli
Author(s) -
Scholl H. P. N.,
Kremers J.
Publication year - 2000
Publication title -
color research and application
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 62
eISSN - 1520-6378
pISSN - 0361-2317
DOI - 10.1002/1520-6378(2001)26:1+<::aid-col30>3.0.co;2-q
Subject(s) - cone (formal languages) , physics , optics , computer science , algorithm
To study the electrophysiological properties of the S‐cone pathway, we adopted a silent substitution paradigm for ERG measurements in an S‐cone (blue‐cone) monochromat. ERG responses to pure S‐cone and rod square wave modulation were measured for different temporal frequencies (1–36 Hz) at 66 cd/m 2 mean luminance and additionally to 1 and 12 Hz modulation at 6.6 cd/m 2 mean luminance. We found rod ERG signals up to a temporal frequency of 30 Hz and S‐cone ERG signals up to 36 Hz. For 1 and 2 Hz temporal modulation, the S‐cone ERG showed a negative deflection after stimulus onset and a positive deflection (OFF‐response) after stimulus offset, whereas for the rod ERG the reverse was the case. At temporal modulations of 6 Hz and above, the first harmonic response showed a phase difference between S‐cone and rod modulation of about 180°. The S‐cone ERG response amplitude for frequencies above 12 Hz with similar photoreceptor contrast was larger than the rod ERG response amplitude. At the lower mean luminance (6.6 cd/m 2 ), the response amplitude of the S‐cone‐ERG was smaller than that found at the higher mean luminance (66 cd/m 2 ), whereas the rod ERG response was larger. The response phase of the S‐cone ERG lagged compared to that at the higher mean luminance (66 cd/m 2 ), whereas the rod ERG response was phase advanced. Our approach can serve as a method to detect differences between the rod and S‐cone pathways and to evaluate protocols of the human S‐cone ERG. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S136–S139, 2001