Transition of the functional brain network related to increasing cognitive demands.
Human Brain Mapping July 1, 2017 Karolina Finc, Kamil Bonna, Monika Lewandowska et al.
As cognitive demands of a working-memory task (n-back) increased, the brain's functional network became less modular, and this change predicted task performance. The number of connector hubs rose while provincial hubs fell, and the default mode network (DMN) increased its connections to other networks while decreasing connections among its own regions. These findings support the global workspace theory, which posits that effortless tasks involve segregated processing, whereas effortful tasks engage distributed networks via long-range connections. The results highlight the DMN's role in network integration during workspace formation.