"Any actual consciousness is in every case not only blindly coupled to its corresponding psychophysical processes, but is akin to it in essential structural properties" (Kohler, 1920, p.193, cf Koffka, 1935, p.62)

"Thus, isomorphism, a term implying equality of form, makes the bold assumption that the 'motion of the atoms and molecules of the brain ' are not 'fundamentally different from thoughts and feelings' but in their molar aspects, considered a processes in extension, identical." (Koffka, 1935, p.62)

Some older forms of isomorphism come from Mach and Hering