title: BOLD signal change and contrast reversing frequency: an event-related fMRI study in human primary visual cortex.
abstract: It is believed that human primary visual cortex (V1) increases activity with increasing temporal frequency of a visual stimulus. Two kinds of visual stimulus were used in the previous studies, one is patterned-flash stimulus with a fixed onset period and an increasing average luminance with the increase of temporal frequency, the other is contrast reversing flickering checkerboard or grating with a constant average luminance across different temporal frequencies. That hemodynamic responses change as a function of reversal frequency of contrast reversing checkerboard is at odds with neurophysiological studies in animals and neuroimaging studies in humans. In the present study, we addressed the relationship between reversal frequency of contrast reversing checkerboard and hemodynamic response in human V1 using an event-related experimental paradigm and found that the transient characteristics of blood oxygenation level dependent response in human V1 depended very little on the reversal frequency of a contrast reversing checkerboard.
authors.affiliation: Department of Psychology, School of Social Sciences, Tsinghua University, Beijing, China; Laboratory for Cognitive Brain Mapping, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama, Japan.
authors.forename: Pei
authors.initials: P
authors.lastname: Sun
authors.affiliation: Department of Psychology, School of Social Sciences, Tsinghua University, Beijing, China.
authors.forename: Jianfei
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Psychology, School of Social Sciences, Tsinghua University, Beijing, China; Department of Computer Science, Tsinghua University, Beijing, China.
authors.forename: Shichun
authors.initials: S
authors.lastname: Guo
authors.affiliation: Medical School, Tsinghua University, Beijing, China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Chen
authors.affiliation: Center for Biomedical Imaging Research, Tsinghua University, Beijing, China.
authors.forename: Le
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Psychology, School of Social Sciences, Tsinghua University, Beijing, China.
authors.forename: Shimin
authors.initials: S
authors.lastname: Fu
mesh_terms: D000328:Adult; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood*; D012815:Signal Processing, Computer-Assisted; D013997:Time Factors; D014793:Visual Cortex / Q000502:physiology*
chemical_list: D010100:Oxygen