title: Differential BOLD activity associated with subjective and objective reports during "blindsight" in normal observers.
abstract: The study of conscious visual perception invariably necessitates some means of report. Report can be either subjective, i.e., an introspective evaluation of conscious experience, or objective, i.e., a forced-choice discrimination regarding different stimulus states. However, the link between report type and fMRI-BOLD signals has remained unknown. Here we used continuous flash suppression to render target images invisible, and observed a long-lasting dissociation between subjective report of visibility and human subjects' forced-choice localization of targets ("blindsight"). Our results show a robust dissociation between brain regions and type of report. We find subjective visibility effects in high-order visual areas even under equal objective performance. No significant BOLD difference was found between correct and incorrect trials in these areas when subjective report was constant. On the other hand, objective performance was linked to the accuracy of multivariate pattern classification mainly in early visual areas. Together, our data support the notion that subjective and objective reports tap cortical signals of different location and amplitude within the visual cortex.
authors: Department of Neurobiology, Weizmann Institute of Science, 76100 Rehovot, Israel. g.hesselmann@gmail.com
authors: Guido
authors: G
authors: Hesselmann
authors: Martin
authors: M
authors: Hebart
authors: Rafael
authors: R
authors: Malach
mesh_terms: D000328:Adult; D001766:Blindness / Q000503:physiopathology*; D001923:Brain Chemistry / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D010100:Oxygen / Q000097:blood*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology; D012160:Retina / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen