Pattern adaptation in detection and discrimination

Abstract

Previous findings indicate that detection and discrimination of sine wave gratings do not occur at a common site. The effects of pattern adaptation are fundamentally different for detection and discrimination,1 and frequency discrimination is based on the object spatial frequencies, whereas contrast detection thresholds are based on the retinal spatial frequencies.2 These findings raise the question: are the effects of pattern adaptation on frequency discrimination3 tied to the object spatial frequencies or to the retinal spatial frequencies? We were unable to replicate Regan and Beverley's results. However, we were able to replicate the well-known perceived spatial frequency shift, which also entails spatial frequency comparisons, and found that it depends on the retinal (not object) spatial frequencies of the test and adapt gratings. Finally, we show that the perceived spatial frequency shift predicts that frequency discrimination thresholds should be altered by pattern adaptation but that the primary predicted effect should be enhancement of frequency discrimination sensitivity at the adapting frequency and not dimunition of frequency discrimination sensitivity away from the adapting frequency as Regan and Beverley reported.