Colour Vision as a Scientific Problem

Abstract

Our understanding of the environment largely based on interpretations
of visual qualities, like contrast, form, and movement.
No such property would be perceived were it not for the differences
in colour (including white, grey and black). The qualities of colour
or qualia belong to the realities of personal experience.
One may, however, sometimes wonder about the link between ones
conscious experience of colours, e.g. the redness of an apple,
and the stimulation of the eye by electromagnetic radiation.
Is there a causal relationship between a physical property of the apples
surface, the evoked neural activity and my perception of red?
Is the spectral reflectance of the coloured surface the salient parameter,
or is the activation of certain nerve cells the more essential?
Or should we talk not so much about cause and effect, but rather,
of complex scenes and neural states, of correlation and co-variation?
Below we shall discuss some of these questions in the light
of psychophysics and modern neuroscience (see also Valberg, 2001).