Contrast and stimulus duration dependence of perceptual surround suppression in older adults

Abstract

Most natural visual tasks involve the extraction of visual features from suprathreshold contrast backgrounds, hence an understanding of how ageing impacts on contrast mechanisms is essential to understand elderly visual function. Previous studies have revealed increased perceptual surround suppression of contrast in older adults. We aimed to determine whether such age-related effects depend on the centre or surround stimulus contrast as the neurophysiological mechanisms underpinning contrast-contrast suppression depend on such contrast relationships. We also measured surround suppression of contrast for longer duration and shorter duration stimuli to explore for effects of surround adaptatio..