Role of the Default Mode Network in Cognitive Transitions
Verity Smith, Daniel J Mitchell, John Duncan
Cerebral Cortex June 21, 2018 DOI: 10.1093/cercor/bhy167 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Sample size | 24 |
| Population | Healthy adults |
| Topics | Default mode network |
| Citations | 173 |
| Key findings | The default mode network shows large increases during brief rests and task restarts after rest, in addition to task switches, suggesting it encodes scene, episode, or context rather than being limited to internally focused thought. |
Abstract
A frequently repeated finding is that the default mode network (DMN) shows activation decreases during externally focused tasks. This finding has led to an emphasis in DMN research on internally focused self-relevant thought processes. A recent study, in contrast, implicates the DMN in substantial externally focused task switches. Using functional magnetic resonance imaging, we scanned 24 participants performing a task switch experiment. Whilst replicating previous DMN task switch effects, we also found large DMN increases for brief rests as well as task restarts after rest. Our findings are difficult to explain using theories strictly linked to internal or self-directed cognition. In line with principal results from the literature, we suggest that the DMN encodes scene, episode or context, by integrating spatial, self-referential, and temporal information. Context representations are strong at rest, but rereference to context also occurs at major cognitive transitions.