title: A neural marker of perceptual consciousness in infants.
abstract: Infants have a sophisticated behavioral and cognitive repertoire suggestive of a capacity for conscious reflection. Yet, demonstrating conscious access in infants remains challenging, mainly because they cannot report their thoughts. Here, to circumvent this problem, we studied whether an electrophysiological signature of consciousness found in adults, corresponding to a late nonlinear cortical response [~300 milliseconds (ms)] to brief pictures, already exists in infants. We recorded event-related potentials while 5-, 12-, and 15-month-old infants (N = 80) viewed masked faces at various levels of visibility. In all age groups, we found a late slow wave showing a nonlinear profile at the expected perceptual thresholds. However, this late component shifted from a weak and delayed response in 5-month-olds (starting around 900 ms) to a more sustained and faster response in older infants (around 750 ms). These results reveal that the brain mechanisms underlying the threshold for conscious perception are already present in infancy but undergo a slow acceleration during development.
authors.affiliation: Laboratoire de Sciences Cognitives et Psycholinguistique, EHESS/CNRS/ENS-DEC, 75005 Paris, France. sid.kouider@ens.fr
authors.forename: Sid
authors.initials: S
authors.lastname: Kouider
authors.forename: Carsten
authors.initials: C
authors.lastname: Stahlhut
authors.forename: Sofie V
authors.initials: SV
authors.lastname: Gelskov
authors.forename: Leonardo S
authors.initials: LS
authors.lastname: Barbosa
authors.forename: Michel
authors.initials: M
authors.lastname: Dutat
authors.forename: Vincent
authors.initials: V
authors.lastname: de Gardelle
authors.forename: Anne
authors.initials: A
authors.lastname: Christophe
authors.forename: Stanislas
authors.initials: S
authors.lastname: Dehaene
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Dehaene-Lambertz
mesh_terms: D000328:Adult; D001921:Brain / Q000254:growth & development* / Q000502:physiology; D003243:Consciousness / Q000502:physiology*; D004569:Electroencephalography; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009474:Neurons / Q000502:physiology*; D010465:Perception / Q000502:physiology*; D010470:Perceptual Masking; D010775:Photic Stimulation