title: Accessing Real-Life Episodic Information from Minutes versus Hours Earlier Modulates Hippocampal and High-Order Cortical Dynamics.
abstract: It is well known that formation of new episodic memories depends on hippocampus, but in real-life settings (e.g., conversation), hippocampal amnesics can utilize information from several minutes earlier. What neural systems outside hippocampus might support this minutes-long retention? In this study, subjects viewed an audiovisual movie continuously for 25 min; another group viewed the movie in 2 parts separated by a 1-day delay. Understanding Part 2 depended on retrieving information from Part 1, and thus hippocampus was required in the day-delay condition. But is hippocampus equally recruited to access the same information from minutes earlier? We show that accessing memories from a few minutes prior elicited less interaction between hippocampus and default mode network (DMN) cortical regions than accessing day-old memories of identical events, suggesting that recent information was available with less reliance on hippocampal retrieval. Moreover, the 2 groups evinced reliable but distinct DMN activity timecourses, reflecting differences in information carried in these regions when Part 1 was recent versus distant. The timecourses converged after 4 min, suggesting a time frame over which the continuous-viewing group may have relied less on hippocampal retrieval. We propose that cortical default mode regions can intrinsically retain real-life episodic information for several minutes.
authors.affiliation: Princeton Neuroscience Institute and.|Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Psychology, University of Toronto, Toronto, ON, CanadaM5S 3G3.
authors.forename: C J
authors.initials: CJ
authors.lastname: Honey
authors.affiliation: Princeton Neuroscience Institute and.|Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: E
authors.initials: E
authors.lastname: Simony
authors.affiliation: Princeton Neuroscience Institute and.|Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Arcaro
authors.affiliation: Princeton Neuroscience Institute and.|Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Norman
authors.affiliation: Princeton Neuroscience Institute and.|Department of Psychology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: U
authors.initials: U
authors.lastname: Hasson
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000502:physiology*; D005260:Female; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D057567:Memory, Long-Term / Q000502:physiology*; D008570:Memory, Short-Term / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009483:Neuropsychological Tests; D013997:Time Factors; D014741:Video Recording; D014796:Visual Perception / Q000502:physiology; D055815:Young Adult
keywords: declarative memory; functional connectivity; intersubject correlation; naturalistic; timescales