Abstract

It has been shown that saccades play an important role in visual tasks, but they do not simply improve resolution of the display. To understand their role, I studied not only the way in which texture perception benefits from saccades, but also the patterns of saccades that are most beneficial. The displays (55) consisted of 1515 randomly oriented T's and L's. The T's formed a random polygonal shape (target) in the central 24 of the display. Eye movements were recorded while subjects estimated both the size and the shape of the target and were under instructions to (1) SCAN the display with saccades or (2) maintain the line of sight in the center without saccades (STAY). The results are as follows: (1) SCAN performance improved with increasing display duration; (2) STAY performance did not improve with increasing display duration longer than 2 s; (3) scanning improved performance for 5 s durations; (4) scanning improved the ability to detect texture patterns; (5) retinal image transients, created by flickering (2 Hz) or jumping (0.5 Hz, 15 ft. [4.57 m] peak-to-peak amplitude) the display, improved performance somewhat for size discrimination but not for shape discrimination; (6) boundary scanning was more beneficial for discrimination than other scanning patterns.

© 1990 Optical Society of America