Brain

All brains come in dual form;
{,{}}
(right,left)=(emotional,analytical)
Sometimes this mapping is flipped;
(right,left)=(analytical,emotional)
Like the split in mathematics;
(Algebra,Geometry)
Algebra for analytical, geometry for emotional.
Like the split in computers;
(Programs,Operating System)
Programs for algebra, OS for geometry.
Emotions set the overall mood by using hormones.
Thus the material base for the dual split is science;
(Physics, Chemistry)
Chemistry sets the geometry for physics (electricity) to operate in.

An M6 brain should unite around M3, like ETT.
M3=E3/H3
SE3/SH3=3!2!1!0!/2^3=12/8=3/2
Would 3/2 symmetry correspond to color perception?
Basically there is only one color to start with;
{gray}
Then it seperates into a mediated duality;
{gray} -> {black,gray,white}
Then white seperates into 3 colors;
{white} -> {yellow,blue,red}
Each color pair also get their own mediation;
{yellow,orange,red}
{yellow,green,blue}
{red,purple,blue}
Thus 3/2 colors, {yellow,red,blue}/{black,white}, define a 3D coordinate system, 3D space.
Each color gets an axis, and {black,white} gives intensity like {-,+}
Like the universe, a brain that perceives 3 colors obeys M3.

Although the color symmetry obeys 3/2, it doesn't necessarily mean light is essential for a brain to evolve.
As ETT shows, sound also obeys the same symmetry.
It seems the brain opens up a seperate 3D phase-space to solve each problem.
3D aspect of hearing is clearly visible in the conic spiral shape of cochlea in ear.
Then there must be other 3/2 modules in the brain to deal with other cognition tasks.
Sense comes in 5 types;
{see,hear,taste,touch,smell}
I think consciousness has to be added in this list.
Even then I think there is one missing, considering M6.
Taste has 3 colors;
{sweet,sour,salty}
With taste intensity we again get 3/2 symmetry.
I regarded 'bitter' as extreme sour.
Touch has 3 colors?
{elastic,stick,inelastic}
Smell comes from taste, therefore obeys the same symmetry.