Open AccessConscious processing of auditory regularities induces a pupil dilation
Author(s) -
Marion Quirins,
Clémence Marois,
Mélanie Valente,
Magali Seassau,
Nicolas Weiss,
Imen Karoui,
JeanRémy Hochmann,
Lionel Naccache
Publication year - 2018
Publication title -
scientific reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.24
H-Index - 213
ISSN - 2045-2322
DOI - 10.1038/s41598-018-33202-7
Subject(s) - pupillary response , pupil , dilation (metric space) , consciousness , pupillometry , contrast (vision) , novelty , cognitive psychology , psychology , time dilation , audiology , neuroscience , computer science , social psychology , medicine , artificial intelligence , mathematics , classical mechanics , combinatorics , theory of relativity , physics
Pupil dilation has been reliably identified as a physiological marker of consciously reportable mental effort. This classical finding raises the question of whether or not pupil dilation could be a specific somatic signature of conscious processing. In order to explore this possibility, we engaged healthy volunteers in the ‘local global’ auditory paradigm we previously designed to disentangle conscious from non-conscious processing of novelty. We discovered that consciously reported violations of global (inter-trials) regularity were associated with a pupil dilation effect both in an active counting task and in a passive attentive task. This pupil dilation effect was detectable both at the group-level and at the individual level. In contrast, unreported violations of this global regularity, as well as unreported violations of local (intra-trial) regularity that do not require conscious access, were not associated with a pupil dilation effect. We replicated these findings in a phonemic version of the ‘local global’. Taken together these results strongly suggest that pupil dilation is a somatic marker of conscious access in the auditory modality, and that it could therefore be used to easily probe conscious processing at the individual level without interfering with participant’s stream of consciousness by questioning him/her.