Biology Reference
In-Depth Information
hand, the final results, the immediate substrata of the sensations,
are themselves of a different nature; and hence that somewhere
along the route the three independent results of stimulus are
transformed into processes of a different kind and composition.
As to these processes, nothing can be said with certainty, in the
writer's opinion, except that in them the colourless sensation
has some outstanding physiological significance (von Kries,
1911
,
pp. 431-432).
It will be seen that the duplicity theory offered by von Kries,
like the Young-Helmholtz colour theory, had little to say about the
actual neurophysiological colour processing beyond the receptor
level. This ignorance is perhaps best illustrated by Helmholtz's
(
1896
) final version of the Young-Helmholtz colour theory where he
simply suggested that the colour-related processes from each receptor
were independently transmitted to the brain through isolated nerve
fibres.
