Feedback connections, which will not be discussed here, can, of course, further increase the power of an information processing system.

The term ``receptive field'' usually corresponds to a well-defined region in the input (stimulus) space, with the contribution of the various points in that space to the output of the current processing stage described by a pattern of weights and an optional nonlinearity.

Webster's Dictionary has: cho.rus 'ko-r-*s, 'ko.r- n [L, ring dance, chorus, fr. Gk choros] 1a: a company of singers and dancers in Athenian drama participating in or commenting on the action. In a chorus, unlike in a Pandemonium [35], the contributions of the individual actors are in harmony with each other (see Figure 8). [3] uses the expression ``chorus of instances'' in his discussion of the theory of representation due to [27].

The basic operation of Chorus is related computationally to a dimensionality-reducing data analysis procedure known as multidimensional scaling, or MDS [36]; see [9]. The additional system of long-range connections can support a path-based variety of MDS [31]. As a result, a scheme based on distances to prototypes may inherit from MDS the desirable properties of low-dimensional output space and faithful representation of shape-space similarities between objects [6].