Lateral connection structuring by excitatory and inhibitory spike-timing-dependent plasticity (STDP).

<p>(A) Schematic figures of connections between the output layer and the lateral layer. In the simulation, each layer consists of 20 neurons. (B) The effect of crosstalk noise on different lateral structures. Analytical results are shown as bold lines, and the results from simulations are shown as dotted lines. (C) Minor source detection with different lateral structures. Because the specialization index is not well defined for a network with random lateral connections, the average synaptic weights from source A to those output neurons that prefer source A were measured instead. (D) Synaptic weight development at three connections. In the left and right columns, panels show synaptic weights of excitatory/inhibitory synapses projected to the neuron group 1 (top) and group 2 (bottom). In the middle graph, panels correspond to excitatory synapses projected from the neuron group 1 (top) and group 2 (bottom). In all panels, thin lines indicate the development of individual synapses, thick lines represent average weights onto output neurons, and colors indicate A-neurons (blue), B-neurons (red), and Background-neurons (orange). (E, F) Performance of the network with different lateral structures in noisy signal detection (E) and minor signal detection (F). Here (and only here), a pre-learned network is used to investigate responses for various inputs.