Re: Homing Pigeons? Try Homing Crocodiles...

[Andreas Johansson <andreasj@gmail.com>]

On 10/1/07, Mickey Rowe;893-2446 <mrowe@lifesci.ucsb.edu> wrote:

> Back to Dan:
>
> } This is of course assuming that magnetic fields aren't interpreted
> } as a fifth visual band (after red, green, blue and UV),
>
> Ouch ouch ouch ouch ouch!  Ouch.  Ouch.  We can*not* currently say
> much of anything about the way birds might categorize colors (again
> even given that you'll go out on the limb to attribute experiences to
> them that are anything remotely like what we understand as
> "experience").  The general thinking among color vision scientists is
> that "red", "green", and "blue" are peculiarities of human vision.
> Whether that's true is a bugger-all hard question to address.  And so
> virtually no one has even tried.  Ironically one of the few animals
> widely cited as having provided us some evidence is the domestic
> pigeon.  Given comparisons of spectral lights (that is lights that
> have all of their energy concentrated over a narrow range of the
> spectrum), the wavelength at which humans might define the category
> distinction between blue and green is not similarly a border between
> two categories of pigeon vision.  Of course studies done more recently
> than that work (which was carried out in the 1970s) indicates that
> there is a huge variation among humans as to where that category
> boundary should lie.  There are stimuli that one person will say is
> completely blue with no hint of green and another person will say is
> completely green with no hint of blue.  We need to figure this out in
> people before trying to figure it out in other animals.

A great many of the world's languages don't bother with different
words for "blue" and "green". To speakers of such languages there
apparently *is* no category difference between them, suggesting that
"red", "green", and "blue" are particularities not of human vision but
of some culturally conditioned ways of thinking about colour. I'll try
and hound down a reference tomorrow.

Closer to home, some people insist that indigo is a colour separate
from violet and blue. Myself, I simply can't see it as other than
bluish violet or violetish blue, yet I score as well as they on
colour-vision tests.

-- 
Andreas Johansson

Why can't you be a non-conformist just like everybody else?