title: Visual adaptation and the cone flicker electroretinogram.
abstract: This study examined the hypothesis that changes in the response properties of the human cone ERG during light adaptation represent the recovery of cone system responsiveness toward a dark-adapted value after an initial decrease in responsiveness at adapting field onset. The electroretinographic (ERG) responses to 31.1 Hz flicker were obtained under both dark-adapted and light-adapted conditions for stimulus luminances ranging from -1.42(-)+0.82 log cd sec/m2. At low stimulus luminances, flicker ERG amplitudes were larger under dark-adapted than under light-adapted conditions, consistent with the hypothesis. However, at high stimulus luminances, flicker ERG amplitudes obtained under light-adapted conditions were approximately double those recorded from the dark-adapted eye. Therefore, the increase in cone ERG amplitude that occurs during light adaptation at high stimulus luminances does not represent a return toward a dark-adapted level but instead entails a substantial enhancement above the dark-adapted value, by a mechanism that is presently unidentified.
authors.affiliation: Department of Ophthalmology, University of Illinois Chicago College of Medicine.
authors.forename: N S
authors.initials: NS
authors.lastname: Peachey
authors.forename: K R
authors.initials: KR
authors.lastname: Alexander
authors.forename: G A
authors.initials: GA
authors.lastname: Fishman
mesh_terms: D000328:Adult; D003623:Dark Adaptation / Q000502:physiology*; D004596:Electroretinography; D005425:Flicker Fusion / Q000502:physiology*; D006801:Humans; D008027:Light; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000502:physiology*