Figure 1. Circuit motifs and simple circuit composed of motifs.

(A) Circuit motifs are excitatory self-recurrence (top) and shared inhibition (bottom). I_i denotes an external input. (B) Connectivity of a simple WTA circuit, consisting of two excitatory units that compete through shared inhibition. (C) More compact notation to denote the circuit shown in (B). Each excitatory element receives an external input.