a neuron, most commonly found in the striate cortex, that has a receptive field consisting of an elongated center region and two elongated flanking regions. The response of a simple cell to stimulation in the center of the receptive field is the opposite of its response to stimulation in the flanking zones. This means that a simple cell responds best to an edge or a bar of a particular width and with a particular direction and location in the visual field. Also called simple cortical cell. Compare complex cell.