Using more rigorous forced-choice psychophysical methods, we have found that psychometric functions are relatively steep. The curve shown here (red triangles) is typical of peripheral visual performance. Performance drops from 95% correct to 55% correct for just a 20% increase in spatial frequency, which means that the cutoff frequency for a 75% criterion would be subject to only about +/- 10% uncertainty, just as we find for method of adjustment.

Recalling that the Nyquist frequency of a sampling array varies as the square root of density, a 10% reduction in resolution acuity corresponds to a reduction in sampling density of about 20%, which hopefully is of some clincial significance.

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.