Re-imagining the future: repetition decreases hippocampal involvement in future simulation

Valerie van Mulukom, Daniel L. Schacter, Michael C. Corballis, Donna Rose Addis

    Research output: Contribution to journalArticle

    23 Citations (Scopus)
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    Abstract

    Imagining or simulating future events has been shown to activate the anterior right hippocampus (RHC) more than remembering past events does. One fundamental difference between simulation and memory is that imagining future scenarios requires a more extensive constructive process than remembering past experiences does. Indeed, studies in which this constructive element is reduced or eliminated by “pre-imagining” events in a prior session do not report differential RHC activity during simulation. In this fMRI study, we examined the effects of repeatedly simulating an event on neural activity. During scanning, participants imagined 60 future events; each event was simulated three times. Activation in the RHC showed a significant linear decrease across repetitions, as did other neural regions typically associated with simulation. Importantly, such decreases in activation could not be explained by non-specific linear time-dependent effects, with no reductions in activity evident for the control task across similar time intervals. Moreover, the anterior RHC exhibited significant functional connectivity with the whole-brain network during the first, but not second and third simulations of future events. There was also evidence of a linear increase in activity across repetitions in right ventral precuneus, right posterior cingulate and left anterior prefrontal cortex, which may reflect source recognition and retrieval of internally generated contextual details. Overall, our findings demonstrate that repeatedly imagining future events has a decremental effect on activation of the hippocampus and many other regions engaged by the initial construction of the simulation, possibly reflecting the decreasing novelty of simulations across repetitions, and therefore is an important consideration in the design of future studies examining simulation.
    Original languageEnglish
    Article numbere69596
    Number of pages10
    JournalPLoS ONE
    Volume8
    Issue number7
    DOIs
    Publication statusPublished - 23 Jul 2013

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    hippocampus
    Hippocampus
    Chemical activation
    Brain
    Parietal Lobe
    Gyrus Cinguli
    Scanning
    Data storage equipment
    Prefrontal Cortex
    Magnetic Resonance Imaging
    brain

    Bibliographical note

    This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

    Keywords

    • fMRI
    • Imagination
    • Memory
    • Episodic memory
    • Episodic future though
    • episodic simulation

    Cite this

    Re-imagining the future : repetition decreases hippocampal involvement in future simulation. / van Mulukom, Valerie; Schacter, Daniel L.; C. Corballis, Michael; Addis, Donna Rose.

    In: PLoS ONE, Vol. 8, No. 7, e69596, 23.07.2013.

    Research output: Contribution to journalArticle

    van Mulukom, Valerie ; Schacter, Daniel L. ; C. Corballis, Michael ; Addis, Donna Rose. / Re-imagining the future : repetition decreases hippocampal involvement in future simulation. In: PLoS ONE. 2013 ; Vol. 8, No. 7.
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