Adaptation and attention in higher visual perception

Differences in the low-level image statistics of environmental scenes contain sufficient information to characterize different types of environments. Briefly displayed visual scenes can be strongly influenced by adaptation to the statistical characteristics of the prevailing visual input. We have previously reported an apparent processing boundary between basic categories of natural and man-made scenes. In the present study, we examine if this adaptation-induced bias in the categorization into natural vs. man-made scenes reflects distinct processing boundaries between these categories. During a rapid parallel multi-image detection task we singled out one target group’s (man-made or natural) current state of categorization. Adaptation to spatial frequency contents along different orientations mimicking the overall statistical spectrum of a given environment adjusts human visual sensitivity only within the adapted category, influencing the categorization of parallel processed scenes, corrupting accurate detection along with processing speed. These category bound adjustments reveal a highly efficient processing mechanism within the visual system to rapidly extract category information as a result of removing redundant information to accentuate “low-level” statistical differences deviating from the mean. Our results reveal distinct processing boundaries between natural and man-made scenes, suggesting non-opponent processed categories.