Mike Scoles asked for a reference on the color vision question. I found some but this abstract seemed to provide the best summary...
---------------------------------------------------------------------- N: 1995-95017-169 DT: Dissertation-Abstract TI: Photoreceptors maximally sensitive to UV light in three species of rodents. AU: Deegan,-Jess-Fulton,-Ii SO: Dissertation-Abstracts-International:-Section-B:-The-Sciences-and-Engineering. 1995 Sep; Vol56(3-B): 1735. AB: Three species of Rodents (Rattus norvegicus, Meriones unguiculatus, Mus musculus; rat, gerbil & mouse; respectively) were tested for the ability to sense and use ultraviolet (UV) light using both electrophysiological and behavioral techniques. The results were in contrast to previous research, showing the animals possess a second cone photopigment--maximal sensitivity to UV light (maximum sensitivity at about 360 nm). The paper provides a brief review of research in the area of UV vision and the vision of the species in question. The electrophysiological experiments were based on a variation of fast flicker photometry, involving the recording of an evoked potential from the cornea. The behavioral experiments were based on a simple forced-choice paradigm involving a three-choice discrimination task. The results of the electrophysiological experiments yielded spectral sensitivity (photopic and scotopic) and temporal sensitivity (photopic and scotopic) curves for each species. The behavioral experiments yielded spectral sensitivity curves, as well as tests of color discrimination. The results indicate that each species possesses a rod photopigment with maximum sensitivity at about 498 nm, which functions independently from the two photopigments found to operate under photopic conditions. For each species it was confirmed that there was a photopigment with maximum sensitivity in the middle-wavelength part of the spectrum: rat and mouse lambda max = 512 nm (Neitz & Jacobs, 1986) and gerbil lambda max = 493 nm (Jacobs & Neitz, 1989). More importantly, the evidence presented here leads one to the conclusion that each species has a photopigment with maximum sensitivity in the UV part of the spectrum (lambda max = 360 nm). This evidence includes tests of the independent adaptability of the two photopic photopigments, eliminating possible spurious explanations (i.e., fluorescence, photoproducts, beta-bands). ------------------------------------------------------------------- ---------------------- Kenneth M. Steele, Ph.D. [EMAIL PROTECTED] Dept. of Psychology Appalachian State University Boone, NC 28608 USA --- You are currently subscribed to tips as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED]
