Transition of the functional brain network related to increasing cognitive demands.
Karolina Finc, Kamil Bonna, Monika Lewandowska, Tomasz Wolak, Jan Nikadon, Joanna Dreszer, Włodzisław Duch, Simone Kühn
Human Brain Mapping July 1, 2017 DOI: 10.1002/hbm.23621 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Intervention | n-back task |
| Topics | Default mode network |
| Keywords | FMRI Functional connectivity Global workspace theory Graph theory Modularity N-back Network-based statistic Working memory |
| Key findings | Network modularity decreased with increasing cognitive demands during an n-back task, and this change predicted behavioral performance; the default mode network increased connectivity to other networks while decreasing connectivity within itself. |
Abstract
Network neuroscience provides tools that can easily be used to verify main assumptions of the global workspace theory (GWT), such as the existence of highly segregated information processing during effortless tasks performance, engagement of multiple distributed networks during effortful tasks and the critical role of long-range connections in workspace formation. A number of studies support the assumptions of GWT by showing the reorganization of the whole-brain functional network during cognitive task performance; however, the involvement of specific large scale networks in the formation of workspace is still not well-understood. The aims of our study were: (1) to examine changes in the whole-brain functional network under increased cognitive demands of working memory during an n-back task, and their relationship with behavioral outcomes; and (2) to provide a comprehensive description of local changes that may be involved in the formation of the global workspace, using hub detection and network-based statistic. Our results show that network modularity decreased with increasing cognitive demands, and this change allowed us to predict behavioral performance. The number of connector hubs increased, whereas the number of provincial hubs decreased when the task became more demanding. We also found that the default mode network (DMN) increased its connectivity to other networks while decreasing connectivity between its own regions. These results, apart from replicating previous findings, provide a valuable insight into the mechanisms of the formation of the global workspace, highlighting the role of the DMN in the processes of network integration. Hum Brain Mapp 38:3659-3674, 2017. © 2017 Wiley Periodicals, Inc.