title: Cortical activity is more stable when sensory stimuli are consciously perceived.
abstract: According to recent evidence, stimulus-tuned neurons in the cerebral cortex exhibit reduced variability in firing rate across trials, after the onset of a stimulus. However, in order for a reduction in variability to be directly relevant to perception and behavior, it must be realized within trial--the pattern of activity must be relatively stable. Stability is characteristic of decision states in recurrent attractor networks, and its possible relevance to conscious perception has been suggested by theorists. However, it is difficult to measure on the within-trial time scales and broadly distributed spatial scales relevant to perception. We recorded simultaneous magneto- and electroencephalography (MEG and EEG) data while subjects observed threshold-level visual stimuli. Pattern-similarity analyses applied to the data from MEG gradiometers uncovered a pronounced decrease in variability across trials after stimulus onset, consistent with previous single-unit data. This was followed by a significant divergence in variability depending upon subjective report (seen/unseen), with seen trials exhibiting less variability. Applying the same analysis across time, within trial, we found that the latter effect coincided in time with a difference in the stability of the pattern of activity. Stability alone could be used to classify data from individual trials as "seen" or "unseen." The same metric applied to EEG data from patients with disorders of consciousness exposed to auditory stimuli diverged parametrically according to clinically diagnosed level of consciousness. Differences in signal strength could not account for these results. Conscious perception may involve the transient stabilization of distributed cortical networks, corresponding to a global brain-scale decision.
authors.affiliation: Cognitive Neuroimaging Unit (U992), INSERM, Gif-sur-Yvette 91191, France; Direction des Sciences du Vivant, I2BM, NeuroSpin Center, Commissariat à l'Energie Atomique, Gif sur Yvette 91191, France; Laboratory of Cognitive Neuroscience, Department of Life Sciences, Brain Mind Institute, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; aaron.schurger@gmail.com.
authors.forename: Aaron
authors.initials: A
authors.lastname: Schurger
authors.affiliation: Cognitive Neuroimaging Unit (U992), INSERM, Gif-sur-Yvette 91191, France; Direction des Sciences du Vivant, I2BM, NeuroSpin Center, Commissariat à l'Energie Atomique, Gif sur Yvette 91191, France; Université Paris-Sud 11, 91405 Orsay, France;
authors.forename: Ioannis
authors.initials: I
authors.lastname: Sarigiannidis
authors.affiliation: Institut du Cerveau et de la Moelle Épinière, INSERM U1127, 75013 Paris, France; Institut du Cerveau et de la Moelle Épinière, CNRS UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Université de Paris 6, 75013 Paris, France; Department of Neurophysiology, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France; and.
authors.forename: Lionel
authors.initials: L
authors.lastname: Naccache
authors.affiliation: Cognitive Neuroimaging Unit (U992), INSERM, Gif-sur-Yvette 91191, France; Direction des Sciences du Vivant, I2BM, NeuroSpin Center, Commissariat à l'Energie Atomique, Gif sur Yvette 91191, France; Institut du Cerveau et de la Moelle Épinière, INSERM U1127, 75013 Paris, France; Institut du Cerveau et de la Moelle Épinière, CNRS UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie, Université de Paris 6, 75013 Paris, France;
authors.forename: Jacobo D
authors.initials: JD
authors.lastname: Sitt
authors.affiliation: Cognitive Neuroimaging Unit (U992), INSERM, Gif-sur-Yvette 91191, France; Direction des Sciences du Vivant, I2BM, NeuroSpin Center, Commissariat à l'Energie Atomique, Gif sur Yvette 91191, France; Université Paris-Sud 11, 91405 Orsay, France; Collège de France, 75005 Paris, France.
authors.forename: Stanislas
authors.initials: S
authors.lastname: Dehaene
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000503:physiopathology*; D003243:Consciousness / Q000502:physiology*; D003244:Consciousness Disorders / Q000503:physiopathology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D010465:Perception; D010812:Physical Stimulation; D015203:Reproducibility of Results; D012677:Sensation / Q000502:physiology*; D013647:Task Performance and Analysis; D013997:Time Factors; D055815:Young Adult
keywords: consciousness; correlated variability; directional variance; dynamical systems; pattern similarity
references.citation: J Neurosci. 2005 Apr 6;25(14):3661-73
references.pmid: 15814797
references.citation: J Neurosci. 2013 Mar 13;33(11):4672-82
references.pmid: 23486941
references.citation: Science. 2010 Jan 1;327(5961):97-9
references.pmid: 19965385
references.citation: Cogn Neurosci. 2011 Jan 1;2(2):98-113
references.pmid: 22121395
references.citation: Sci Transl Med. 2013 Aug 14;5(198):198ra105
references.pmid: 23946194
references.citation: Science. 2010 Jan 1;327(5961):43-4
references.pmid: 20044565
references.citation: Nat Rev Neurosci. 2001 Apr;2(4):229-39
references.pmid: 11283746
references.citation: Neuron. 2009 Sep 24;63(6):879-88
references.pmid: 19778515
references.citation: Proc Natl Acad Sci U S A. 2009 Feb 3;106(5):1672-7
references.pmid: 19164526
references.citation: Conscious Cogn. 2005 Jun;14(2):390-425
references.pmid: 15950889
references.citation: Chaos. 2012 Dec;22(4):043131
references.pmid: 23278066
references.citation: Science. 1986 Aug 8;233(4764):625-33
references.pmid: 3755256
references.citation: Science. 2010 Oct 1;330(6000):97-101
references.pmid: 20829453
references.citation: J Neurosci. 2014 Mar 19;34(12):4382-95
references.pmid: 24647958
references.citation: Comput Intell Neurosci. 2011;2011:156869
references.pmid: 21253357
references.citation: J Neurosci. 1992 Dec;12(12):4745-65
references.pmid: 1464765
references.citation: Proc Natl Acad Sci U S A. 2002 Jul 9;99(14):9527-32
references.pmid: 12089336
references.citation: Nat Neurosci. 2009 Jan;12(1):70-6
references.pmid: 19029885
references.citation: PLoS Biol. 2005 May;3(5):e141
references.pmid: 15819609
references.citation: J Neurosci. 2008 Nov 26;28(48):12591-603
references.pmid: 19036953
references.citation: PLoS One. 2014;9(1):e85791
references.pmid: 24475052
references.citation: Cogn Neurosci. 2010 Sep;1(3):176-183
references.pmid: 20823938
references.citation: Science. 1998 Dec 4;282(5395):1846-51
references.pmid: 9836628
references.citation: Proc Natl Acad Sci U S A. 1982 Apr;79(8):2554-8
references.pmid: 6953413
references.citation: Curr Biol. 2010 Jan 26;20(2):R61-2
references.pmid: 20129040
references.citation: Neuroimage. 2013 Jun;73:80-94
references.pmid: 23380166
references.citation: Neuropsychologia. 2012 Feb;50(3):403-18
references.pmid: 22230230
references.citation: Neuroimage. 2005 Nov 1;28(2):326-41
references.pmid: 16084117
references.citation: Proc Natl Acad Sci U S A. 2008 Mar 4;105(9):3599-604
references.pmid: 18299568
references.citation: Front Hum Neurosci. 2011 Sep 29;5:107
references.pmid: 22046158
references.citation: Science. 1967 Dec 22;158(3808):1597-600
references.pmid: 6060369
references.citation: J Clin Neurophysiol. 1992 Oct;9(4):456-79
references.pmid: 1464675
references.citation: Nat Neurosci. 2007 Feb;10(2):257-61
references.pmid: 17237774
references.citation: Neuron. 2011 Apr 28;70(2):200-27
references.pmid: 21521609
references.citation: Curr Biol. 2006 Oct 24;16(20):2023-9
references.pmid: 17055981
references.citation: Cognition. 2009 May;111(2):187-211
references.pmid: 19306995
references.citation: Brain. 2012 Apr;135(Pt 4):1308-20
references.pmid: 22226806
references.citation: Curr Biol. 2013 Oct 7;23(19):1914-9
references.pmid: 24076243
references.citation: Nat Neurosci. 2010 Mar;13(3):369-78
references.pmid: 20173745
references.citation: Phys Rev Lett. 2013 Apr 26;110(17):178101
references.pmid: 23679783
references.citation: Proc Natl Acad Sci U S A. 2003 Jul 8;100(14):8520-5
references.pmid: 12829797
references.citation: BMC Neurosci. 2013;14:122
references.pmid: 24125590
references.citation: Proc Natl Acad Sci U S A. 2012 Dec 26;109(52):21504-9
references.pmid: 23236162
references.citation: J Neurosci. 2012 Jan 18;32(3):1061-72
references.pmid: 22262904
references.citation: J Neurosci. 2007 Mar 14;27(11):2858-65
references.pmid: 17360907
references.citation: Nat Neurosci. 2012 Dec;15(12):1729-35
references.pmid: 23103963
references.citation: Neuropsychologia. 2006;44(10):1796-803
references.pmid: 16620886
references.citation: Behav Brain Sci. 1999 Feb;22(1):127-48; discussion 148-96
references.pmid: 11301521
references.citation: Conscious Cogn. 2010 Jun;19(2):674-81
references.pmid: 19828331
references.citation: J Neurosci Methods. 2009 Feb 15;177(1):199-202
references.pmid: 18973774
references.citation: Nat Neurosci. 2009 Dec;12(12):1594-600
references.pmid: 19915566
references.citation: Neuroimage. 2014 Nov 1;101:337-50
references.pmid: 25063731
references.citation: Arch Ital Biol. 2012 Jun-Sep;150(2-3):91-106
references.pmid: 23165871
references.citation: Nature. 1999 Feb 4;397(6718):430-3
references.pmid: 9989408
references.citation: Neuron. 2009 Nov 25;64(4):562-74
references.pmid: 19945397
references.citation: Psychol Sci. 2009 Nov;20(11):1348-55
references.pmid: 19788529
references.citation: Neuropsychol Rehabil. 2005 Jul-Sep;15(3-4):166-74
references.pmid: 16350959
references.citation: Nature. 1997 Apr 10;386(6625):604-8
references.pmid: 9121583
references.citation: J Neurosci. 2008 Mar 5;28(10):2667-79
references.pmid: 18322110
references.citation: Invest Ophthalmol Vis Sci. 2003 May;44(5):2267-76
references.pmid: 12714670
references.citation: Vision Res. 2012 Jan 15;53(1):21-9
references.pmid: 22133595
references.citation: Conscious Cogn. 2012 Mar;21(1):228-37
references.pmid: 22205022
references.citation: Nature. 2004 Apr 15;428(6984):748-51
references.pmid: 15085132
references.citation: Trends Cogn Sci. 2009 Jul;13(7):302-9
references.pmid: 19535283
references.citation: Brain. 2014 Aug;137(Pt 8):2258-70
references.pmid: 24919971
references.citation: J Neurosci. 2001 Feb 15;21(4):1370-7
references.pmid: 11160408
references.citation: PLoS Comput Biol. 2008 Jun;4(6):e1000091
references.pmid: 18551165
references.citation: Proc Natl Acad Sci U S A. 2008 Aug 5;105(31):10984-9
references.pmid: 18664576
references.citation: Neuron. 2007 Jul 5;55(1):131-41
references.pmid: 17610822
references.citation: Nat Neurosci. 2005 Oct;8(10):1391-400
references.pmid: 16158062
references.citation: PLoS Comput Biol. 2014 Apr;10(4):e1003553
references.pmid: 24743308
references.citation: J Neurosci. 2012 Jan 18;32(3):799-805
references.pmid: 22262878
references.citation: PLoS Biol. 2007 Oct;5(10):e260
references.pmid: 17896866
references.citation: PLoS Biol. 2009 Mar 17;7(3):e61
references.pmid: 19296722
references.citation: J Neurosci. 2009 Jul 8;29(27):8715-25
references.pmid: 19587278
references.citation: Nat Neurosci. 2013 Nov;16(11):1671-7
references.pmid: 24097038
references.citation: Cereb Cortex. 1998 Mar;8(2):97-107
references.pmid: 9542889
references.citation: Neurosci Biobehav Rev. 2012 Feb;36(2):737-46
references.pmid: 22192881
references.citation: Chaos. 2010 Mar;20(1):013108
references.pmid: 20370263
references.citation: Brain Cogn. 2008 Feb;66(1):91-103
references.pmid: 17664036
references.citation: Neuropsychologia. 2008;46(8):2189-97
references.pmid: 18396301
references.citation: Trends Neurosci. 2000 Nov;23(11):571-9
references.pmid: 11074267