From visual consciousness to spectral absorption in the human retina.
In this paper, we present work that started as an interest in visual consciousness with the study of the blindsight phenomena and color processing. This led us to develop an intraocular reflection and absorption model of the human eye that is sufficient to account for luminance and color detection in blindsight subjects. Luminance and color thresholds were obtained in the good and blind field of hemidecorticated patients under controlled conditions. To determine the role of internal scatter and absorption properties of the human eye we tested the model predictions in three ways. By psychophysical means, by measuring absorption and scatter properties of the human eye, and by building an electromechanical sensor apparatus mimicking Lambertian reflection in the eye. The results of the simulations and measurements support the notion that the sensitivity functions obtained with the hemidecorticated patients can be explained by reflection and absorption properties of the human eye that have not been fully accounted for in the blindsight literature. In the light of such findings, future blindsight experiments must necessarily account for intraocular absorption and reflective properties of the human eye of the type described.
Faubert
J
J
Ecole d'optométrie, Université de Montréal, 3744 rue Jean-Brillant, Montréal, PQ H3T 1P1, Canada. jocelyn.faubert@umontreal.ca
Diaconu
V
V
D003118:Color Perception / Q000502:physiology*; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D011601:Psychophysics; D012160:Retina / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*