a type of neuron in the visual system that depolarizes when a particular stimulus (e.g., red light) comes on in the center of the neuron’s receptive field and when the “opposite” stimulus (e.g., green light) is extinguished in the surrounding zone of the receptive field. Double-opponent cells depolarize when the red light comes on or the green light is extinguished in the center of the receptive field, whereas the same stimuli produce the opposite effects in the receptive field surround.