title: Brains striving for coherence: Long-term cumulative plot formation in the default mode network.
abstract: Many everyday activities, such as engaging in conversation or listening to a story, require us to sustain attention over a prolonged period of time while integrating and synthesizing complex episodic content into a coherent mental model. Humans are remarkably capable of navigating and keeping track of all the parallel social activities of everyday life even when confronted with interruptions or changes in the environment. However, the underlying cognitive and neurocognitive mechanisms of such long-term integration and profiling of information remain a challenge to neuroscience. While brain activity is generally traceable within the short time frame of working memory (milliseconds to seconds), these integrative processes last for minutes, hours or even days. Here we report two experiments on story comprehension. Experiment I establishes a cognitive dissociation between our comprehension of plot and incidental facts in narratives: when episodic material allows for long-term integration in a coherent plot, we recall fewer factual details. However, when plot formation is challenged, we pay more attention to incidental facts. Experiment II investigates the neural underpinnings of plot formation. Results suggest a central role for the brain's default mode network related to comprehension of coherent narratives while incoherent episodes rather activate the frontoparietal control network. Moreover, an analysis of cortical activity as a function of the cumulative integration of narrative material into a coherent story reveals to linear modulations of right hemisphere posterior temporal and parietal regions. Together these findings point to key neural mechanisms involved in the fundamental human capacity for cumulative plot formation.
authors.affiliation: Center for Semiotics, Department for Aesthetics and Communication, Aarhus University, Jens Chr. Skous Vej 2, 8000 Aarhus C, Denmark; Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark; The Interacting Minds Center, Department of Culture and Society, Aarhus University, Jens Chr. Skous Vej 4, 8000 Aarhus C, Denmark. Electronic address: kristian@cfin.dk.
authors.forename: K
authors.initials: K
authors.lastname: Tylén
authors.affiliation: The Interacting Minds Center, Department of Culture and Society, Aarhus University, Jens Chr. Skous Vej 4, 8000 Aarhus C, Denmark; Centre for Languages and Literature, Lund University, Helgonabacken 12, 221 00 Lund, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Christensen
authors.affiliation: Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark; The Interacting Minds Center, Department of Culture and Society, Aarhus University, Jens Chr. Skous Vej 4, 8000 Aarhus C, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Roepstorff
authors.affiliation: Center for Functionally Integrative Neuroscience, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Lund
authors.affiliation: Center for Semiotics, Department for Aesthetics and Communication, Aarhus University, Jens Chr. Skous Vej 2, 8000 Aarhus C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Østergaard
authors.affiliation: Department of Psychology, Hunphrey Hall, 62 Arch St., Queens University, Kingston, Ontario K7L3N6, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Donald
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D002540:Cerebral Cortex / Q000502:physiology*; D032882:Comprehension / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D061212:Memory, Episodic; D011939:Mental Recall / Q000502:physiology*; D033262:Narration; D009415:Nerve Net / Q000502:physiology*; D055815:Young Adult
keywords: Default mode network; Memory; Narrative; fMRI