Abstract

Lateral interactions play a prominent role in the spatial vision of both normal and amblyopic observers. These interactions have generally been reported to be inhibitory in both psychophysical (Cannon and Fullenkamp, 1991; Chubb, Sperling and Solomon, 1989) and physiological ((Kitano et al, 1994; Grinvald et ah, 1994) studies. More recently long range excitatory interactions have been found psychophysically (Polat and Sagi, 1993b, 1994a). The visibility of a small foveally viewed Gabor patch can enhanced by laterally placed Gabor patches of similar orientation. The sign of the effect, enhancement or suppression depends on target and flank separation and on the relative orientation of the target and its flanks. Maximal facilitation of threshold occurs for co-oriented, collinear targets that are separated by several wavelengths of the spatial frequency of the Gabor patches. Interactions occur over distances as large as several degrees.

© 1995 Optical Society of America