Default mode contributions to automated information processing

Abstract

Concurrent with mental processes that require rigorous computation and control, a series of automated decisions and actions govern our daily lives, providing efficient and adaptive responses to environmental demands. Using a cognitive flexibility task, we show that a set of brain regions collectively known as the default mode network play a crucial role in such ÒautopilotÓ behavior, i.e. when rapidly selecting appropriate responses under predictable behavioral contexts. While applying learned rules, the default mode network shows both greater activity and connectivity. Furthermore, functional interactions between this network and hippocampal, parahippocampal areas as well as primary visual cortex correlate with the speed of accurate responses. These findings indicate a memory-based Òautopilot roleÓ for the default mode network, which may have important implications for our current understanding of healthy and adaptive brain processing.Significance Statement: In addition to dealing with variable demands of the environment in everyday life, we are continuously faced with routine, predictable challenges that require fast and effective responses. In an fMRI-based cognitive flexibility task, we show greater activity/connectivity centered on the default mode network during such automated decisionmaking under predictable environmental demands. Furthermore, we report on a significant correlation between this network and hippocampal connectivity, and individual differences in the participantsÕ ability to make automated, fast and accurate responses. Together, these results suggest a novel ÒautopilotÓ role for this network that may have important theoretical implications for our understanding of healthy brain processing in meeting worldly demands.Running on Autopilot

Converging evidence for the role of transmodal cortex in cognition

“…Thus, even though brain activity analyzed by Vidaurre et al (1) takes place at rest, the functional implications of their analysis extend to forms of cognition measured in the context of a task (such as intelligence). A similar conclusion emerges from the study by Vatansever et al (2). The progression to a state of rule-based behavior in the WCST corresponds to a shift in brain activity from an initial focus in frontoparietal regions to those in the DMN (Fig.…”

“…The studies by Vidaurre et al (1) and Vatansever et al (2) in PNAS provide contrasting, yet complementary insights into the role that regions of transmodal cortex, including those in the default mode network (DMN) (3) and the fronto-parietal network (FPN) (4), play in cognition.…”

“…Vatansever et al (2) used task-based fMRI to illustrate how the DMN and FPN work collectively to guide complex behavior. In their study, participants performed the Wisconsin Card Sorting Task (WCST) (5) while brain activity was measured using fMRI.…”

“…Periodically, the rule changes and feedback is used to update the current goal representation. Vatansever et al (2) demonstrate that the FPN is active after a rule change-the "acquisition phase"-suggesting its involvement in encoding the contingencies upon which the sorting decision is based. In later sections of the block-the "application phase"-when the individual understands the rule, activity within the FPN is reduced, and activity within the DMN increases (Fig.…”

“…Therefore, the activity within the DMN corresponds to periods when contingencies determining cognitive decisions are established. Additionally, and importantly, Vatansever et al (2) show that patterns of increased DMN connectivity are also linked to better response latency during correct trials. Together, these results corroborate recent studies showing that the DMN supports external task processing when behavior depends on preexisting representations guiding cognition (6)(7)(8)(9).…”