Figure 1.

Network architecture. Each circle represents a homogeneous population of neurons. The gray oval includes the on-chip populations: two excitatory populations E_att and E_bkg (48 neurons each) and one inhibitory population I (31 neurons). Off-chip populations E1_AER (800 neurons), E2_AER (300 neurons), and I_AER (300 neurons) are simulated in software. Connectivity is specified in terms of the fraction c of source neurons projecting to each target neuron. Projections are drawn to identify synaptic efficacies as excitatory potentiated (J_p), excitatory depressed (J_d), or inhibitory (J_i).