Receptive fields of two neurons in the optic tectum.

<p>a) Receptive field of a neuron recorded at 1210 µm presented as the response to white and black stimuli shown 0–190 ms before. The neuron responded with a short delay to black (40 ms) and with a longer delay to white (130 ms) and therefore could be responsive to decrease in luminance. In this particular case, the stimuli were shown on 15×15 positions which each covered 3.4×3.0 degrees of the visual field. The white subfield (at delay = 130 ms) was 10.8 degrees in size while the black subfield was 14.9 degrees (at delay = 40 ms). b) Receptive field of a neuron recorded at 1090 µm. In this particular case, the stimuli were shown on 15×15 positions which each covered 4.2×3.5 degrees of visual field. Please notice that the black subfield is larger than the white subfield (for this neuron the white subfield was 11.1 degrees in size while the black subfield was 19.4 degrees).