Perhaps the most compelling evidence is simply the reports of what patterns look like in peripheral vision.

When the spatial frequency of the patterns were below the resolution cutoff, they appeared veridically. That is, the subject saw what he was given - a patch of vertical grating containing a few cycles of the pattern. However, when the spatial frequency exceeded the resolution limit, which in this case was about 5.5 cyc/deg, the perceived stimulus looked quite different from the actual stimulus. The pattern was distorted, the orientation was frequently wrong, and the spatial scale of the visible elements was much coarser than the actual stimulus. These sketches are, in my mind, compelling evidence of non-veridical spatial perception - in other words, aliasing - of frequencies beyond the resolution limit.

This non-veridical nature of both spatial perception and motion perception has been reported now by half a dozen or more groups using a variety of test stimuli and viewing conditions.

Slide 1	Slide 2	Slide 3	Slide 4	Slide 5	Slide 6	Slide 7	Slide 8	Slide 9	Slide 10
Slide 11	Slide 12	Slide 13	Slide 14	Slide 15	Slide 16	Slide 17	Slide 18	Slide 19	Slide 20
Slide 21	Slide 22	Slide 23	Slide 24	Slide 25	Slide 26	Slide 27	Slide 28	Slide 29	Slide 30
Slide 31	Slide 32	Slide 33	Slide 34

WWWaveTM 1996
World Wide Web automated virtual environment TM 1996
Kevin Haggerty, Indiana University.