Is conscious perception a continuous or dichotomous phenomenon?

Abstract

Is our conscious visual experience of the world characterised by events that appear suddenly or gradually in our awareness? This apparently simple question has proved difficult to resolve. Inspired by the global neuronal workspace theory, the dichotomous view (e.g. Sergent and Dehaene, 2004) proposes that visual experience is all-or-none, and that someone is always either fully conscious or fully unconscious of visual phenomena. Opposed to this is a graded view (e.g. Overgaard, Rote, Mouridsen, & Ramsøy, 2006) that argues for the existence of diluted states of visual consciousness. Contradictory introspective and theoretical accounts have not been settled in experimental investigations. It was the aim of this thesis to test the proposal that the form of consciousness is dynamic and dependent on the viewing conditions of the observer. To this end, the three experiments reported in this thesis investigated the effect of degradation technique, stimulus type and processing level on conclusions regarding the form of visual consciousness. Further, the possible confounding effect of awareness scale length in this area was examined.