Open Collections

Momeni, Ava

University of British Columbia

Functional magnetic resonance imaging (fMRI) studies typically explore the blood-oxygen-level-dependent (BOLD) signal underlying discrete cognitive processes that occur over milliseconds to a few seconds. However, autobiographical cognition is a protracted process and requires fMRI tasks with longer trials to capture the temporal dynamics of the underlying brain networks. In the current study, we provide an updated analysis of the fMRI data obtained from a published autobiographical event simulation task, with a slow-event-related design (34-second trials), that involved participants recalling past events, imagining past/future events, and completing a semantic association control task. Both versions of the analytical approach, called Principal Component Analysis for fMRI (fMRI-CPCA), used to derive the brain networks involved in the autobiographical event simulation task resulted in four brain networks. Two networks, the Default Mode network, which activated during the autobiographical event simulation conditions but deactivated in the semantic association control condition, and the Multiple Demand network, which peaked early in the trials when external focus to solve the task was required, partially reproduced and extended the previously published results. Two networks, the Maintaining Internal Attention network, which activated when participants had to direct their focus internally to engage in autobiographical event simulation and semantic association, and the Response network, which activated when participants had to make motor responses, were novel and provided new information about the BOLD changes underlying autobiographical event simulation. Overall, our findings reveal that the DMN is not uniquely involved in autobiographical event simulation as it coactivates with the MAIN. However, these two networks do not have redundant functions as in the semantic association control condition, the DMN deactivated while the MAIN activated. Thus, our results highlight that the MAIN consistently shows activation during all periods of maintaining attention to internal mental representations, whereas the DMN shows activation during the simulation of internal events that take one’s own perspective – a process unlikely to be engaged during semantic association. The identification of additional networks by fMRI-CPCA demonstrates how different analytical approaches can provide complementary information and, ultimately, lead to more refined cognitive interpretations of task-based fMRI data.

Text

2024-04-29

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88080

Neuroscience

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/