Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!snorkelwacker.mit.edu!bloom-picayune.mit.edu!18.70.0.226!lfk From: lfk@eastman1.mit.edu (Lee F. Kolakowski) Newsgroups: sci.bio Subject: Re: Primary colors in human color vision Message-ID: Date: 25 Mar 91 16:39:02 GMT References: <00945FE5.1F9B5480@aclcb.purdue.edu> <1991Mar23.193006.22992@pinhead.pegasus.com> <1991Mar24.002117.24100@medisg.Stanford.EDU> <13701@helios.TAMU.EDU> Sender: news@athena.mit.edu (News system) Organization: Mass. Inst. of Tech., Dept. of Chemistry Lines: 43 In-Reply-To: msw1633@zeus.tamu.edu's message of 25 Mar 91 06:38:12 GMT On 25 Mar 91 06:38:12 GMT, msw1633@zeus.tamu.edu (WHITSITT, MARK STEVEN) said: > In article <1991Mar24.002117.24100@medisg.Stanford.EDU>, vangeldr@cmgm.Stanford.EDU (Russ Van Gelder) writes... >>the absorption spectrum of the molecule; Jeremy Nathans (who worked >>out much of the molecular biology and genetics of human color vision) >>has been making site-directed mutants of the color opsins and thinks >>that the relative localization of charge on the retinal is responsible >>for its spectral absorbance. Not just Jeremy Nathans, but several other labs as well. > The idea that the opsin side chains "tune" the retinal then suggests > many interesting variations on color perception. Consider an > individual "A" having a mutation in one of his/her opsins which > tunes the retinal differently than that of individual "B". Would > placing A's eyes in B make B see colors differently than he/she did > before? That is, would a familiar shade of, say, red, be perceived > as a different shade of "red" with respect to the color individual B > was accustomed to? What do ya think? This is true. There are individuals who are color blind who have a wide range of differences in their physcophysical perceptions. These are test by asking persons to adjust two knobs on a device which alters the ratio of red and green which make yellow, and comparing the color to "spectrally pure" yellow. THis test was devised by Lord Rayleigh. It turns out that some of these people have hybrid red/green photoreceptors. Also various mutations in rhodopsin can alter the wavelength at which it is most sensitive. -- Frank Kolakowski ======================================================================= |lfk@athena.mit.edu or lfk@eastman1.mit.edu or kolakowski@wccf.mit.edu| | Lee F. Kolakowski M.I.T. | | Dept of Chemistry Room 18-506 | | 77 Massachusetts Ave. Cambridge, MA 02139 | | AT&T: 1-617-253-1866 #include | ======================================================================= ||Desert Storm - Lasers have made this the cleanest *dirty war* ever.|| =======================================================================