"New" colours possible?

Richard Norman rsnorman at mediaone.net
Wed Oct 31 09:05:00 EST 2001


On Wed, 31 Oct 2001 11:38:28 +0000, "C.J.L. Wolf"
<C.J.L.Wolf at ncl.ac.uk> wrote:

>The genes that determine the spectral sensitivity of L and M - cones are
>on the X - chromosome. Mutations in the genes can alter their spectral
>sensitivity (most males who are 'colourblind' have both L and M cones, but
>either the L or M pigment has mutated to more closely resemble the other,
>impairing their colour vision). Women have 2 X-chromosomes, so can
>potentially have up to 2 different versions of hte L-cone pigment, and 2
>different versions of the M-cone pigment. Lyonisation - random
>inactivation of one X-chromosome in each cell) means that women may
>theoretically have up to 5 cone classes, each with a different spectral
>sensitivity. i.e. L1 L2 M1 M2 S... Gabrielle Jordan and John Mollon
>studied a tetrachromatic female, and showed that she could see colours
>that no-one else could.

JD Mollon is certainly someone who does a lot of work in this area.
However a search of the US National Library of Medicine (PubMed at
http://www.ncbi.nlm.nih.gov/PubMed/) for "Mollon" gave 100 hits, none
of which seemed to be this work.  Searching "Jordan" gave 1184, far
too many to scan, but the combination Mollon and Jordan gave none.  I
also found nothing in the 19 hits on  "tetrachromatic".  Do you have a
citation?

What does it mean "colours that no-one else could [see]".  Does
it mean she could separate test stimuli as looking different when
others thought they looked the same?




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