title: The sensory timecourses associated with conscious visual item memory and source memory.
abstract: Previous event-related potential (ERP) findings have suggested that during visual item and source memory, nonconscious and conscious sensory (occipital-temporal) activity onsets may be restricted to early (0-800 ms) and late (800-1600 ms) temporal epochs, respectively. In an ERP experiment, we tested this hypothesis by separately assessing whether the onset of conscious sensory activity was restricted to the late epoch during source (location) memory and item (shape) memory. We found that conscious sensory activity had a late (>800 ms) onset during source memory and an early (<200 ms) onset during item memory. In a follow-up fMRI experiment, conscious sensory activity was localized to BA17, BA18, and BA19. Of primary importance, the distinct source memory and item memory ERP onsets contradict the hypothesis that there is a fixed temporal boundary separating nonconscious and conscious processing during all forms of visual conscious retrieval.
authors.affiliation: Center for Vital Longevity and School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX 75235, United States. Electronic address: preston6667@gmail.com.
authors.forename: Preston P
authors.initials: PP
authors.lastname: Thakral
authors.affiliation: Department of Psychology, Boston College, United States.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Slotnick
mesh_terms: D000293:Adolescent; D000328:Adult; D003243:Consciousness; D004569:Electroencephalography / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D009778:Occipital Lobe / Q000502:physiology*; D013702:Temporal Lobe / Q000502:physiology*; D013997:Time Factors; D014473:Unconscious, Psychology; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: ERPs; Explicit memory; Implicit memory; Occipital; Temporal; fMRI