Transcript Bag
Why do we think we see “everything”? • Immediate availability at flick of eye/attention • The “world as an outside memory”(O’Regan, 1992) • refrigerator light analogy (N. Thomas) • visual “solipsism” Vision-inverting mirror Erismann (1947) Kohler (1951) Kohler, 1951 Kohler, 1951 Kohler, 1951 Another of the training procedures he adopted was to walk round and round a chair or table, constantly touching it with his body, and frequently changing direction so as to bring both sides into action. It was during an exercise of this kind, on the eighth day of the experiment, that he had his first experience of perceiving an object in its true position. But it was a very strange experience, in that he perceived the chair as being both on the side where it was in contact with his body and on the opposite side. And by this he meant not just that he knew that the chair he saw on his left was actually on his right. He had that knowledge from the beginning of the experiment. The experience was more like the simultaneous perception of an object and its mirror image, although in this case the chair on the right was rather ghost-like. J.G. Taylor, 1962, p. 201-202. (the subject here was Seymour Papert, wearing left-right inverting spectacles, during an experiment he subjected himself to while visiting Taylor in Cape Town in 1953) Why do we think we see “everything”? • Immediate availability at flick of eye/attention • The “world as an outside memory”(O’Regan, 1992) • refrigerator light analogy (N. Thomas) • visual “solipsism” Why is seeing different from other mental phenomena? • Corporality – tight link to body motions • Alerting capacity – transients incontrovertibly grab attention Corporality voluntary motions systematically affect input Don’t see objects but what you can do with them Children’s drawings Boundary completion (H. Intraub) H. Intraub, et al., 1993 ++ Alerting Capacity capacity to peremptorily interfere with cognitive processing visual transients INFORMATION AVAILABLE: m o t io n w Ron o r ient at io n Hotel x z Soda c o lo r y Bag Foot r xxxx Table yyyy MODULES iconic memory INFORMATION AVAILABLE: w Ron Hotel Ron x z Soda select y Soda Bag Foot r INFORMATION ENCODED: Bag Foot Table iconic memory short term visual memory cf. Bundesen, 1990; Gegenfurtner & Sperling, 1993 Luck & Vogel, 1997 BAG CODED? INFORMATION AVAILABLE: m o t io n w Ron o r ient at io n Hotel x z Soda c o lo r y Foot r xxxx yyyy TRANSIENTS IN MODULES.... BAG DISAPPEARS! Table INFORMATION AVAILABLE: w Ron AFTER CHANGE Hotel Ron x z Soda Soda compare y Foot r Table Foot Bag (previously stored) Detecting changes normally • transient indicates location and ‘flavour’ of change. • if object previously coded: • transient indicates change location • comparison can be made • if object not coded • ‘flavor’ can be used to guess at change INFORMATION AVAILABLE: FLICKER w Ron Hotel Ron x z Soda Soda compare y Foot r Table Foot Bag (previously stored) Detecting changes when there are global transients • if object coded: slow search for change location • if object not coded: no hope. Using a global transient • Flicker – Rensink, O’Regan & Clark,1997; 1999 • Eye saccades – Currie, McConkie, Carlson-Radvansky & Irwin, 1995; McConkie & Currie, 1996 • Blinks – O’Regan, Deubel, Clark, Rensink, 1999 • Film cuts – Levin & Simons, 1997 QuickTime™ et un décompresseur Sorenson Video sont requis pour visualiser cette image. D. Simons & D. Levin QuickTime™ et un décompresseur Sorenson Video sont requis pour visualiser cette image. D. Simons & D. Levin QuickTime™ et un décompresseur Cinepak sont requis pour visualiser cette image. D. Simons & D. Levin Using distracting local transients • “Mudsplashes” – O’Regan, Rensink & Clark (Nature, 1999) INFORMATION AVAILABLE: MUDSPLASH w Ron Hotel Ron x z Soda Pepsi compare y Foot r Table Foot Bag (previously stored) Change blindness experiments • Principle: render transients inoperative – Drowned by global transient: flicker, saccade, blink, film cut – Diversion by local transient (mudsplash) – No transient: slow change (R. Chabrier) QuickTime™ et un décompresseur GIF sont requis pour visualiser cette image. Auvray & O’Regan, 2003; Chabrier & O’Regan, unpublished QuickTime™ et un décompresseur Cinepak sont requis pour visualiser cette image. Auvray & O’Regan, 2003; Chabrier & O’Regan, unpublished Recent sources on CB • Visual Cognition 2000, 1/2/3 (Ed. Dan Simons) • Fleeting Memories (Ed. V. Coltheart) MIT Press, 1999 • http://viscog.beckman.uiuc.edu/change/ • http://www.journalofvision/3/1/ Recent issues on CB • implicit memory, unconscious recall • layout • cognitive description • CB in dynamic scenes • iconic memory, masking Why do we think we see “everything”? • • • • Immediate availability at flick of eye/attention The “world as an outside memory”(O’Regan, 1992) refrigerator light analogy (N. Thomas) visual “solipsism” Why is seeing different from other mental phenomena? • Corporality – tight link to body motions • Alerting capacity – transients incontrovertibly grab attention Remembering corporality -- alerting capacity -- Seeing corporality +++ alerting capacity +++ "raw feel" corporality remember see -- alerting capacity -- +++ +++ "raw feel" corporality remember -- alerting capacity -- feel rich + - drive ++ - see +++ +++ Seeing is a SKILL Exercising the sensorimotor contingencies standard view new view Seeing is making an internal representation Seeing is knowing about things to do detailed internal representation standard view Brain creates experience detailed internal representation standard view Brain creates experience detailed internal representation new view Brain creates actions and has knowledge