title: Pattern electroretinogram threshold does not show contrast adaptation.
abstract: Pattern electroretinogram (PERG) thresholds were examined using a swept contrast stimulus method. Stimulus contrast was either continuously changed (swept) from high to low (descending sweep), or from low to high (ascending sweep). Visual evoked potential (VEP) contrast threshold was higher when measured using descending sweeps than when using ascending sweeps. This VEP threshold difference has been attributed to cortical adaptation. Although previous work has reported changes in the PERG amplitude as a function of pre-exposure, we have found no analogous effect on the PERG threshold.
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D004596:Electroretinography / Q000379:methods*; D005074:Evoked Potentials, Visual; D006801:Humans; D008297:Male; D012684:Sensory Thresholds; D014785:Vision, Ocular / Q000502:physiology*