Christof Koch et al study the extent higher order statistics affect human attention in natural stimuli

Wolfgang Einhauser, Ueli Rutishauser, E. Paxon Frady, Swantje Nadler, Peter Konig, and Christof Koch (2006) The relation of phase noise and luminance contrast to overt attention in complex visual stimuli. Journal of Vision, 6 (11): 1148-1158, 2006. CaltechAUTHORS