title: Nonconscious emotional processing involves distinct neural pathways for pictures and videos.
abstract: Facial expressions are known to impact observers' behavior, even when they are not consciously identifiable. Relying on visual crowding, a perceptual phenomenon whereby peripheral faces become undiscriminable, we show that participants exposed to happy vs. neutral crowded faces rated the pleasantness of subsequent neutral targets accordingly to the facial expression's valence. Using functional magnetic resonance imaging (fMRI) along with psychophysiological interaction analysis, we investigated the neural determinants of this nonconscious preference bias, either induced by static (i.e., pictures) or dynamic (i.e., videos) facial expressions. We found that while static expressions activated primarily the ventral visual pathway (including task-related functional connectivity between the fusiform face area and the amygdala), dynamic expressions triggered the dorsal visual pathway (i.e., posterior partietal cortex) and the substantia innominata, a structure that is contiguous with the dorsal amygdala. As temporal cues are known to improve the processing of visible facial expressions, the absence of ventral activation we observed with crowded videos questions the capacity to integrate facial features and facial motions without awareness. Nevertheless, both static and dynamic facial expressions activated the hippocampus and the orbitofrontal cortex, suggesting that nonconscious preference judgments may arise from the evaluation of emotional context and the computation of aesthetic evaluation.
authors.affiliation: Laboratoire de Sciences Cognitives et Psycholinguistique, CNRS/EHESS/DEC-ENS, Paris 75005, France. nathan.faivre@ens.fr
authors.forename: Nathan
authors.initials: N
authors.lastname: Faivre
authors.forename: Sylvain
authors.initials: S
authors.lastname: Charron
authors.forename: Paul
authors.initials: P
authors.lastname: Roux
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lehéricy
authors.forename: Sid
authors.initials: S
authors.lastname: Kouider
mesh_terms: D000293:Adolescent; D000328:Adult; D001364:Awareness / Q000502:physiology*; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D001931:Brain Mapping; D004644:Emotions; D005149:Facial Expression; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology*; D010100:Oxygen; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics; D011930:Reaction Time; D014741:Video Recording; D055815:Young Adult
chemical_list: D010100:Oxygen