Integration without awareness: expanding the limits of unconscious processing

Abstract

Human conscious awareness is commonly seen as the climax of evolution. However, what function – if any – it serves in human behavior is still debated. One of the leading suggestions holds that the cardinal function of conscious awareness is integration across numerous inputs and levels of analysis – including the multitude of features and objects in a complex scene – into a unified, coherent, and meaningful perceptual experience. Here we demonstrate, however, that integration of objects and their background scenes can be achieved without awareness of either. In a group of human observers, complex scenes including incongruent objects were faster than normal scenes to escape perceptual suppression induced in a binocular rivalry setting known as Continuous Flash Suppression. We conclude that visual awareness is not needed for object-background integration or for processing the likelihood of an object to appear within a given semantic context, but may be needed for dealing with novel situations.