Model, receptive field organization and figure-ground segregation.

<p><b>A</b>: The model consists of two separate feature channels (Feat-1 and Feat-2) each with two layers, which are unidirectionally connected (arrows). The white regions in the two lower squares indicate the stimulus input (FG input). Black regions provide no input to the model. In the two layers of the model, the light grey central squares depict the figure region and dark grey regions the background. <b>B</b>: Layer-1 neurons have a centre receptive field, i.e. they are driven by one input pixel. Layer-2 neurons have an excitatory centre and inhibitory surround receptive field. The central small black circles represent a neuron in the first and second layer of the model. The small grey square represents one input pixel. Blue arrows indicate point-to-point (retinotopic), excitatory connections and orange region represent the inhibitory connections from layer 1 to layer 2. <b>C</b>: Spike responses of the neurons in the first and second layer to figure-ground stimulus. Arrows point to the responses of neurons (small circles) lying on the figure (red traces) and background (green traces) regions.