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Cueing Attention after the Stimulus Is Gone Can Retrospectively Trigger Conscious Perception

2012; Elsevier BV; Volume: 23; Issue: 2 Linguagem: Inglês

10.1016/j.cub.2012.11.047

1879-0445

Claire Sergent, Valentin Wyart, Mariana Babo-Rebelo, Laurent Cohen, Lionel Naccache, Catherine Tallon‐Baudry,

Neural dynamics and brain function

Is our perceptual experience of a stimulus entirely determined during the early buildup of the sensory representation, within 100 to 150 ms following stimulation [1Lamme V.A. Why visual attention and awareness are different.Trends Cogn. Sci. 2003; 7: 12-18Abstract Full Text Full Text PDF PubMed Scopus (704) Google Scholar, 2Lamme V.A. Roelfsema P.R. The distinct modes of vision offered by feedforward and recurrent processing.Trends Neurosci. 2000; 23: 571-579Abstract Full Text Full Text PDF PubMed Scopus (1484) Google Scholar]? Or can later influences, such as sensory reactivation, still determine whether we become conscious of a stimulus [3Rees G. Kreiman G. Koch C. Neural correlates of consciousness in humans.Nat. Rev. Neurosci. 2002; 3: 261-270Crossref PubMed Scopus (511) Google Scholar, 4Dehaene S. Changeux J.-P. Naccache L. Sackur J. Sergent C. Conscious, preconscious, and subliminal processing: a testable taxonomy.Trends Cogn. Sci. 2006; 10: 204-211Abstract Full Text Full Text PDF PubMed Scopus (1202) Google Scholar]? Late visual reactivation can be experimentally induced by postcueing attention after visual stimulus offset [5Sergent C. Ruff C.C. Barbot A. Driver J. Rees G. Top-down modulation of human early visual cortex after stimulus offset supports successful postcued report.J. Cogn. Neurosci. 2011; 23: 1921-1934Crossref PubMed Scopus (25) Google Scholar]. In a contrary approach from previous work on postcued attention and visual short-term memory, which used multiple item displays [6Sperling G. The information available in brief visual presentations.Psychological Monographs: General and Applied. 1960; 74: 1-29Crossref Google Scholar, 7Sligte I.G. Scholte H.S. Lamme V.A. Are there multiple visual short-term memory stores?.PLoS ONE. 2008; 3: e1699Crossref PubMed Scopus (295) Google Scholar], we tested the influence of postcued attention on perception, using a single visual stimulus (Gabor patch) at threshold contrast. We showed that attracting attention to the stimulus location 100 to 400 ms after presentation still drastically improved the viewers' objective capacity to detect its presence and to discriminate its orientation, along with drastic increase in subjective visibility. This retroperception effect demonstrates that postcued attention can retrospectively trigger the conscious perception of a stimulus that would otherwise have escaped consciousness. It was known that poststimulus events could either suppress consciousness, as in masking, or alter conscious content, as in the flash-lag illusion. Our results show that conscious perception can also be triggered by an external event several hundred ms after stimulus offset, underlining unsuspected temporal flexibility in conscious perception.