PSYB51H3 Lecture Notes - Lecture 5: Subtractive Color, Trichromacy, Ganglion Cell
Document Summary
Humans see a narrow range of electromagnetic spectrum between the wavelengths of about 400-700 nanometers. Color is the result of the interaction of a physical stimulus with a particular nervous system. Three steps to color perception: detection, wavelengths must be detected. Cones differ in the photopigment they carry and as a result they differ in their sensitivity to light of different wavelengths. Short wavelength cones (s cones) have a peak at 420nm. Medium wavelength cones (m cones) peak at 535 nm. Long wavelength cones (l cones) peak at 565nm. Rods work in dimmer (scotopic) light and has a different sensitivity profile peaking at 500nm: discrimination, must be able to tell the difference between one wavelength (or mixture of wavelengths) and another. Principle of univariance: an infinite set of different wavelength intensity combinations can elicit exactly the same response from a single type of photoreceptor. One photoreceptor type cannot make color discriminations based on wavelength.
