Luminance and opponent color contributions to visual detection and to temporal and spatial integration: comment.
King-Smith and Carden have postulated a "luminance system" or achromatic channel in the visual system which has a temporal response better than  the other channels, and which also responds to high spatial frequencies better than the other channels. All evidence, both psychophysical and electrophysiological, indicates that these properties are contradictory.
D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity