Surround-induced foveal afterimage pulsation: evidence for a long-range neural effect.
We demonstrate that an afterimage resulting from a strong foveal light flash can be made to pulsate by luminance modulation of a surrounding annulus as far as 8 deg away. Afterimage pulsation persists even if all artifacts due to pupil size, stray light and simultaneous contrast are ruled out. This suggests an origin by a long-range neural process acting from the remote surround. The effect is interpreted in terms of an adaptive gain control optimizing the responses of visual cells.
Otte
Tobias
T
Brain Research Unit, Department of Neurology, University Hospital, Freiburg, Breisacher Strabe 64, D-79106 Freiburg, Germany. Tobias.Otte@zfn-brain.uni-freiburg.de
Valberg
Arne
A
Spillmann
Lothar
L
D000328:Adult; D000360:Afterimage; D000368:Aged; D015350:Contrast Sensitivity; D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D008029:Lighting; D009483:Neuropsychological Tests; D009903:Optical Illusions; D010775:Photic Stimulation; D011601:Psychophysics; D011680:Pupil; D012044:Regression Analysis