Yes / Purpose: We introduce a method for determining the impulse response function (IRF)
of the ERG derived from responses to temporal white noise (TWN) stimuli.
Methods: This white noise ERG (wnERG) was recorded in participants with normal
trichromatic vision to full-field (Ganzfeld) and 39.38 diameter focal stimuli at mesopic
and photopic mean luminances and at different TWN contrasts. The IRF was obtained
by cross-correlating the TWN stimulus with the wnERG.
Results: We show that wnERG recordings are highly repeatable, with good signal-tonoise
ratio, and do not lead to blink artifacts. The wnERG resembles a flash ERG
waveform with an initial negativity (N1) followed by a positivity (P1), with amplitudes
that are linearly related to stimulus contrast. These N1 and N1-P1 components
showed commonalties in implicit times with the a- and b-waves of flash ERGs. There
was a clear transition from rod- to cone-driven wnERGs at ~1 photopic cd.m 2. We
infer that oscillatory potentials found with the flash ERG, but not the wnERG, may
reflect retinal nonlinearities due to the compression of energy into a short time period
during a stimulus flash.
Conclusion: The wnERG provides a new approach to study the physiology of the
retina using a stimulation method with adaptation and contrast conditions similar to
natural scenes to allow for independent variation of stimulus strength and mean
luminance, which is not possible with the conventional flash ERG.
Translational Relevance: The white noise ERG methodology will be of benefit for
clinical studies and animal models in the evaluation of hypotheses related to cellular
redundancy to understand the effects of disease on specific visual pathways.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/15488 |
| Date | January 2017 |
| Creators | Zele, A., Feigle, B., Kambhampati, P., Aher, A., McKeefry, Declan J., Parry, Neil R.A., Maguire, John, Murray, I.J., Kremers, Jan |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Published version |
| Rights | (c) 2017 The Authors. This is an Open Access article distributed under the Creative Commons CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0) |
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