title: Steady-state and dynamic network modes for perceptual expectation.
abstract: Perceptual expectation can attenuate repetition suppression, the stimulus-induced neuronal response generated by repeated stimulation, suggesting that repetition suppression is a top-down modulatory phenomenon. However, it is still unclear which high-level brain areas are involved and how they interact with low-level brain areas. Further, the temporal range over which perceptual expectation can effectively attenuate repetition suppression effects remains unclear. To elucidate the details of this top-down modulatory process, we used two short and long inter-stimulus intervals for a perceptual expectation paradigm of paired stimulation. We found that top-down modulation enhanced the response to the unexpected stimulus when repetition suppression was weak and that the effect disappeared at 1,000 ms prior to stimulus exposure. The high-level areas involved in this process included the left inferior frontal gyrus (IFG_L) and left parietal lobule (IPL_L). We also found two systems providing modulatory input to the right fusiform face area (FFA_R): one from IFG_L and the other from IPL_L. Most importantly, we identified two states of networks through which perceptual expectation modulates sensory responses: one is a dynamic state and the other is a steady state. Our results provide the first functional magnetic resonance imaging (fMRI) evidence of temporally nested networks in brain processing.
authors.affiliation: Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Republic of Korea.
authors.forename: Uk-Su
authors.initials: US
authors.lastname: Choi
authors.affiliation: Kansei Fukushi Research Institute, Tohoku Fukushi University, Sendai, Japan.
authors.forename: Yul-Wan
authors.initials: YW
authors.lastname: Sung
authors.affiliation: Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Republic of Korea.|Kansei Fukushi Research Institute, Tohoku Fukushi University, Sendai, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ogawa
mesh_terms: D001921:Brain / Q000502:physiology; D001931:Brain Mapping; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010465:Perception / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult