title: Dissociation of part-based and integrated neural responses to faces by means of electroencephalographic frequency tagging.
abstract: In order to isolate the repetition suppression effects for each part of a whole-face stimulus, the left and right halves of face stimuli were flickered at different frequency rates (5.88 or 7.14 Hz), changing or not changing identity at every stimulation cycle. The human electrophysiological (electroencephalographic) responses to each face half increased in amplitude when different rather than repeated face half identities were presented at every stimulation cycle. Contrary to the repetition suppression effects for whole faces, which are usually found over the right occipito-temporal cortex, these part-based repetition suppression effects were found on all posterior electrode sites and were unchanged when the two face halves were manipulated by separation, lateral misalignment, or inversion. In contrast, intermodulation components (e.g. 7.14-5.88 = 1.26 Hz) were found mainly over the right occipito-temporal cortex and were significantly reduced following the aforementioned manipulations. In addition, the intermodulation components decreased substantially for face halves belonging to different identities, which form a less coherent face than when they belong to the same face identity. These observations provide objective evidence for dissociation between part-based and integrated (i.e. holistic/configural) responses to faces in the human brain, suggesting that only responses to integrated face parts reflect high-level, possibly face-specific, representations.
authors.affiliation: Psychological Sciences Research Institute and Institute of Neuroscience, Université catholique de Louvain, 10 Place du Cardinal Mercier, Louvain la Neuve, 1348, Belgium.
authors.forename: Adriano
authors.initials: A
authors.lastname: Boremanse
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Norcia
authors.forename: Bruno
authors.initials: B
authors.lastname: Rossion
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: face perception; frequency tagging; human; intermodulation; repetition suppression; steady-state visual evoked potential