Macaque V1 neurons can signal `illusory' contours.

Describes a view of primary visual cortex (V1) based on measurements of neural responses in V1 to illusory contour patterns using Macaque monkeys. Measurement of responses of neurons to patterns sharing the same luminance; Significance of a frequency-doubled response; Index of response-dependence on spatial phase; Response to illusory contours defined by line gratings.