Default mode network electrophysiological dynamics and causal role in creative thinking
E. Bartoli, E. Devara, H. Q. Dang, R. Rabinovich, Raissa K Mathura, A. Anand, B. Pascuzzi, Joshua A Adkinson, Yoed N. Kenett, K. Bijanki, S. Sheth, Ben Shofty
Brain : a journal of neurology June 18, 2024 DOI: 10.1093/brain/awae199 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study using intracranial stereo-EEG recordings with direct cortical stimulation Peer reviewed |
|---|---|
| Sample size | 13 |
| Population | Human patients undergoing stereo-EEG monitoring |
| Intervention | Direct cortical stimulation |
| Topics | Default mode network |
| Key findings | The default mode network was recruited during both mind wandering and the alternate uses task, with task-specific spatiotemporal dynamics: alternate uses engaged the DMN early and mind wandering later, and gamma power changes were driven mainly by lateral DMN sites. Direct cortical stimulation of DMN regions preferentially reduced the originality of alternate uses responses without affecting fluency or mind wandering, which the authors argue supports a causal role for the DMN in divergent thinking. |
Abstract
Abstract The default mode network (DMN) is a widely distributed, intrinsic brain network thought to play a crucial role in internally directed cognition. The present study employs stereo-EEG in 13 human patients, obtaining high resolution neural recordings across multiple canonical DMN regions during two processes that have been associated with creative thinking: spontaneous and divergent thought. We probe these two DMN-associated higher cognitive functions through mind wandering and alternate uses tasks, respectively. Our results reveal DMN recruitment during both tasks, as well as a task-specific dissociation in spatiotemporal response dynamics. When compared to the fronto-parietal network, DMN activity was characterized by a stronger increase in gamma band power (30–70 Hz) coupled with lower theta band power (4–8 Hz). The difference in activity between the two networks was especially strong during the mind wandering task. Within the DMN, we found that the tasks showed different dynamics, with the alternate uses task engaging the DMN more during the initial stage of the task, and mind wandering in the later stage. Gamma power changes were mainly driven by lateral DMN sites, while theta power displayed task-specific effects. During alternate uses task, theta changes did not show spatial differences within the DMN, while mind wandering was associated to an early lateral and late dorsomedial DMN engagement. Furthermore, causal manipulations of DMN regions using direct cortical stimulation preferentially decreased the originality of responses in the alternative uses task, without affecting fluency or mind wandering. Our results suggest that DMN activity is flexibly modulated as a function of specific cognitive processes and supports its causal role in divergent thinking. These findings shed light on the neural constructs supporting different forms of cognition and provide causal evidence for the role of DMN in the generation of original connections among concepts.