What does change blindness teach us about consciousness?

Abstract

In a recent opinion article, Simons and Rensink [1xChange blindness: past, present, future. Simons, D.J. and Rensink, R.A. Trends Cogn. Sci. 2005; 9: 16–20Abstract | Full Text | Full Text PDF | PubMed | Scopus (489)See all References[1] argue that change blindness (CB) is logically compatible with the existence of detailed internal representations underlying visual experience. They criticize O'Regan and Noe [2xA sensorimotor approach to vision and visual consciousness. O'Regan, J.K. and Noe, A. Behav. Brain Sci. 2001; 24: 883–975CrossrefSee all References[2] for assuming, fallaciously as they say, that CB demonstrates conclusively that there are no internal representations. This misrepresents our approach, but also raises important issues and calls for a response.There is no proof, supplied by CB or anything else, that vision does not rely on internal representations. Whether, and to what degree, vision requires representations is, or should be regarded as, an open empirical question [3xBeyond the grand illusion: what change blindness really teaches us about vision. Noe, A. et al. Visual Cogn. 2000; 7: 93–106CrossrefSee all References[3]. We have argued that the existence of detailed internal representations does not (and could not) explain visual consciousness. As has been widely discussed, there is an explanatory gap; no one has even the roughest sketch of the way neural processes in the brain (representational or otherwise) could ‘generate’ visual experience. Given this, we argue not that there are no representations, but that the category ‘representation’ should be demoted within the context of visual theory [3xBeyond the grand illusion: what change blindness really teaches us about vision. Noe, A. et al. Visual Cogn. 2000; 7: 93–106CrossrefSee all References[3]. We break with the orthodox view by proposing a framework within which vision, rather than being a process whereby the brain produces detailed representations of what is experienced, is taken to be an activity of exploring the environment drawing on sensorimotor skills [2xA sensorimotor approach to vision and visual consciousness. O'Regan, J.K. and Noe, A. Behav. Brain Sci. 2001; 24: 883–975CrossrefSee all References, 4xChange blindness. Simons, D.J. and Levin, D.T. Trends Cogn. Sci. 1997; 1: 261–267Abstract | Full Text PDF | PubMedSee all References].From the standpoint of this new approach, CB is not a surprising finding. Unless you are applying sensorimotor skill to a feature, you aren't experiencing it; and if you aren't experiencing it, it isn't surprising that you should fail to notice its change. CB lends support to our view – as against traditional representationalism – not because CB logically entails our view, or because it is incompatible with representationalism, but because our view does a better job of explaining CB; indeed, it would predict it.We have always been aware that CB is logically compatible with the existence of internal representations [3xBeyond the grand illusion: what change blindness really teaches us about vision. Noe, A. et al. Visual Cogn. 2000; 7: 93–106CrossrefSee all References[3]. It is never the case, in science, that a single phenomenon overthrows a deeply entrenched thesis; the logical complexity of theories guarantees that different adjustments in the face of unanticipated findings are always possible. What is clear is that CB is surprising from the standpoint of traditional orthodoxy. That is why so many thinkers (including, it should be noted, Simons [5xThe dynamic representation of scences. Rensink, R.A. Visual Cogn. 2000; 7: 17–42CrossrefSee all References[5] and Rensink [6xAction in Perception. Noe, A. See all References[6]) leapt, in the first flush of discovery, to the conclusion that CB undermines the representational approach. CB requires adjustments to be made to the orthodox view and so, to that degree at least, it weighs against orthodoxy.What does CB teach us about visual consciousness? The jury is still out. Recent work indicates that information about detail in a scene to which subjects demonstrate CB might in fact be represented insofar as it is available to the subjects if properly probed [7xSee all References, 8xWhy visual awareness and attention are different. Lamme, V. Trends Cogn. Sci. 2003; 7: 12–18Abstract | Full Text | Full Text PDF | PubMed | Scopus (481)See all References]. Do subjects experience this represented detail, as some have suggested [8xWhy visual awareness and attention are different. Lamme, V. Trends Cogn. Sci. 2003; 7: 12–18Abstract | Full Text | Full Text PDF | PubMed | Scopus (481)See all References[8]? Empirical and conceptual progress is needed to answer this question.