title: Effect of stimulus contrast on simultaneous steady-state pattern reversal electroretinogram and visual evoked response.
abstract: We studied the effect of stimulus pattern contrast on the simultaneously recorded pattern reversal electroretinogram (PERG) and pattern reversal visual evoked response (PVER) at 5 check sizes. The stimulus contrast ranged from 24 to 95% in 6 steps of 0.1- or 0.15-log unit increments. PERG amplitude showed a linear increase with an increase in pattern contrast at all check sizes. PVER amplitude showed an increase up to a certain pattern contrast, but was saturated upon further increase in stimulus contrast at all check sizes. The PERG amplitude-check size function curve showed a flattened, inverted-U shape only with the highest contrast and low-pass filter shape or flat shape with lower contrasts. The PVER amplitude-check size function curve showed an inverted-U shape (bandpass filter shape) at all contrasts. These characteristics to the changes in contrast and the spatial frequency tuning suggest that PVER is processed in a different location of visual pathway than PERG.
authors.affiliation: Schepens Eye Research Institute, Boston, Mass 02114.
authors.forename: S
authors.initials: S
authors.lastname: Tetsuka
authors.forename: O
authors.initials: O
authors.lastname: Katsumi
authors.forename: M
authors.initials: M
authors.lastname: Mehta
authors.forename: H
authors.initials: H
authors.lastname: Tetsuka
authors.forename: T
authors.initials: T
authors.lastname: Hirose
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012160:Retina / Q000502:physiology