Spatial influences on colour opponent contributions to pattern detection.
The contribution of colour opponent mechanisms to detection thresholds is investigated at different spatial frequencies by presenting monochromatic, sinusoidal gratings on a uniform white background. Colour opponent mechanisms, characterised by a triple peaked spectral sensitivity function, determine threshold at low spatial frequencies (below 1 c/deg) and their contribution flattens the Weber function. They display low pass spatial frequency characteristics, becoming relatively more sensitive than non-opponent mechanisms as spatial frequency decreases. Colour opponent contributions are not revealed when the test grating and background are presented dichoptically.
Mullen
K T
KT
Physiological Laboratory, University of Cambridge, England.
D003118:Color Perception / Q000502:physiology*; D005556:Form Perception / Q000502:physiology*; D006801:Humans; D008027:Light; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D012684:Sensory Thresholds / Q000502:physiology; D013053:Spectrophotometry