title: Temporal dynamics of repetition suppression to individual faces presented at a fast periodic rate.
abstract: Periodic presentation of visual stimuli leads to a robust electrophysiological response on the human scalp exactly at the periodic stimulation frequency, a response defined as a "steady-state visual evoked potential" (SSVEP, Regan, 1966). However, recent studies have shown that SSVEPs over the (right) occipito-temporal cortex are reduced when the same individual face is repeated at periodic rates of 3 to 9 Hz compared to when different faces are presented (Rossion, 2014). Here, we characterized the temporal dynamics of this repetition suppression effect. We presented different face identities at a rate of 5.88 Hz (stimulus onset asynchrony of 170 ms) for 15 s, followed by the repetition of the exact same face at this rate for 35 s. Compared to a stimulation sequence with different faces only, there was a large and specific decrease of the 5.88 Hz response when the same face was repeated at that rate. This effect was observed over the left and right occipito-temporal cortex, but not over medial occipital electrode sites where SSVEPs are typically measured. In the right hemisphere, this decrease occurred abruptly, i.e., within half a second following the introduction of the same-identity stimulation, with no further decrease until the end of the stimulation. These observations indicate that the SSVEP recorded over high-level visual areas to periodic stimulation is not steady but rather adapts immediately and fully following the repetition of the same individual face, supporting a bottom-up, stimulus-driven account of repetition suppression effects.
authors.affiliation: University of Louvain, Belgium. Electronic address: dan.nemrodov@uclouvain.be.
authors.forename: Dan
authors.initials: D
authors.lastname: Nemrodov
authors.affiliation: University of Louvain, Belgium.
authors.forename: Corentin
authors.initials: C
authors.lastname: Jacques
authors.affiliation: University of Louvain, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Rossion
mesh_terms: D000328:Adult; D001931:Brain Mapping; D004192:Discrimination, Psychological / Q000502:physiology*; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005145:Face; D005260:Female; D005583:Fourier Analysis; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017711:Nonlinear Dynamics; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D013702:Temporal Lobe / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
keywords: Adaptation; EEG; Face perception; Fast periodic stimulation; Individual face discrimination; Repetition suppression