Vertebrate brain theory

7.5  The colour term and the neuronal colour triangle of the nucleus olivaris

Color analysis using neural color triangles is the main reason why we can see a colored television picture in color at all, even though it consists only of the three primary colors red, green and blue, or alternatively of three other primary colors.

There are currently no light-emitting diodes whose monochromatic light colour can be controlled electronically. If such light-emitting diodes existed and their use in television screens or in computers and mobile phones were economical, it would be possible to actually show the color that is supposed to be seen on the screen in every pixel.

In the neurosciences, the concept of colour is hotly debated. From a mathematician's point of view, colour is something that exists outside the brain and can be described in a strictly scientific way. The colour of light is determined by the wavelength. And this wavelength exists independently of the vertebrate brain. But vertebrates have developed an algorithm to determine the wavelength of light seen.

And as a side result of this algorithm, they have gained the ability to assign a color value to a wavelength mixture, because a wavelength mixture in the neuronal color triangle of the nucleus olivaris creates the same impression as the pure, i.e. monochromatic, replacement color through additive color mixing. Here the vertebrates abstract from the physically exact concept of color, which is bound to a concrete wavelength, and form classes of color mixtures to which they assign a well-defined color.

A similar observation is made in mathematics. The combination of number differences from natural numbers leads to the class of integers. According to this class, each integer represents an infinitely large set of number differences, but is in principle treated as a single object. A temperature of -5 °C will not give anyone the impression that an infinite set of temperature differences is meant. Similarly, we do not imagine an infinite number of colour mixtures under the colour yellow, which is ultimately referred to as yellow. The group-theoretical interpretation of such class formations is trivially neglected in real life and is only fully understood by the theorists of the corresponding field of science. In this respect, the theory of colour may well contain group-theoretical aspects.

In the future it will be useful to subdivide the cerebellum according to its predominant mode of operation. One of these modes of operation is signal inversion, which is used in vestibulo- and spinocerebellum, among others. We could call such cerebellum structures inversion cerebellum. On the other hand, if the imprinting of purkinj groups is the main task of such a cerebellar structure, we would also call it imprinting cerebellum. This would apply to the Pontocerebellum. With regard to the color recognition described above, the cerebellum works as a pure inversion system.