How do we update information when comprehending narratives, and how does that change as we age?¶
Readers construct situation models of the events described in a text and update these models at points of change. We evaluated age-related changes in situation model updating by having 20 young and 20 older adults undergo fMRI scanning and read narratives that contained either character or spatial shifts. Participants then responded to recognition probes which occurred along unchanged or changed dimensions relative to the prior shifts, and sometimes even when there was no shift. Slower responses to changed versus unchanged probes indicate incremental updating, where only the changed information is cleared from working memory. Uniformly slower responses to both changed and unchanged probes indicate global updating, where the entire situation model is cleared regardless of what changed. Narrative shifts were associated with slower response times overall with older adults being generally slower. Younger adults showed a mix of incremental/global updating profiles slowing selectively for changed probes. Older adults showed a global profile slowing for both unchanged and changed probes, replicating prior work. Neurally, older adults showed elevated, more sustained BOLD activity than young adults in the DMN regions. This was true both when narrative shifts occurred and in response to memory probes. Young adults' neural activity corroborated this behavioral profile, showing evidence of both incremental and global updating; older adults' neural activity did not. We discuss possible implications of this age-related dissociation between behavioral and neural signatures of situation model updating. These results reveal distinct neural mechanisms between younger and older adult updating situation models.
Keywords: situation model updating, cognitive aging, fMRI, narrative comprehension
Upadhyayula, Bailey, Su, Flores, Reagh & Zacks (in preparation). Interactive results