Computation in Neural Nets - Understanding Understanding: Essays on Cybernetics and Cognition - page 80

FIGURE 30. Arrival of fibers at the target layer of an action network of cell
assemblies.

()
()

Nu
Nu

x 1

x 2

N ......

x

() Nu

xi

......

We shall define a “distribution function” k ( x , u i ) which is simply that frac-
tion of all the fibers that emerge from x and terminate at u i :

() Nu

N

xi

( ) = kxu ,

i

x

or

() = ( ) Nu kxuN , . (97)

xi i x

Clearly, if we take the summation over all targets u i reached by fibers
emerging from x , we must obtain all fibers emerging from x :

ÂÂ Â

() = ( ) ( ) NNu = k x u , NNk x u = , ,

x x i i x x i

all i all i all i