The effects of blur adaptation on visual search performance

Visual system adapts to the current viewing context by changing its sensitivity to stimulus properties. These adjustments play a key role in optimizing visual processing and influencing perceptual judgments. Most of the studies examining the perceptual consequences of adaptation by measuring the effects of short-term adaptation on visual search tasks have reported limited improvement in search performance. In the current study, we examined whether visual search performance can be improved as a result of lengthened adaptation. Using naturalistic stimuli, we measured visual search performance (reaction times & accuracy) after a brief (10s) or prolonged (20 minutes) adaptation to blur and compared it to baseline search performance without adaptation. We adapted participants to a blurred video, created by shifting each frame’s original 1/f amplitude spectrum slope by -0.5. Each participant completed 3 blocks. In each block, after the initial adaptation (10s or 20 mins), participants were asked to perform a total of 66 search trials. In each trial, participants searched for a patch with different slopes of the amplitude spectrum than the blurred background after a 2s top-up adaptation. Patches' amplitude spectrum slopes were changed from -1 to 0.1 in steps of 0.1 and 6 trials were included for each slope per block. Search performance was averaged across 3 blocks. Brief adaptation had no discernable effect on reaction times and accuracy, whereas prolonged adaptation improved search accuracy but not reaction times. Our preliminary results suggest that achieving appropriate states of adaptation may be required for enhancing visual search performance.