The role of saccades in the perception of texture patterns.

We studied the perception of texture patterns when observers used saccadic eye movements to scan the display and when the line of sight was maintained in the display center without saccades. Saccades improved the discrimination of the size and the shape of a central randomly-shaped polygon for display durations > 1 sec. Saccades were more important with textures that did not readily segregate into target and background regions than with those that did. Directing saccades to the curvature extrema of the central target figure was more useful than directing them elsewhere. Saccades did not enhance texture segregation, but rather improved the discriminability of individual target and background elements by overcoming lateral interference. To the extent that strong lateral interference is inevitable with poorly-segregating textures, our results show that serial inspection is best carried out by sequences of saccades, not by sequences of attention shifts.