Integration and segregation of large-scale brain networks during short-term task automatization

Abstract

The human brain is organized into large-scale functional networks that can flexibly reconfigure their connectivity patterns, supporting both rapid adaptive control and long-term learning processes. However, it has remained unclear how short-term network dynamics support the rapid transformation of instructions into fluent behaviour. Comparing fMRI data of a learning sample (N=70) with a control sample (N=67), we find that increasingly efficient task processing during short-term practice is associated with a reorganization of large-scale network interactions. Practice-related efficiency gains are facilitated by enhanced coupling between the cingulo-opercular network and the dorsal attention network. Simultaneously, short-term task automatization is accompanied by decreasing activation of the fronto-parietal network, indicating a release of high-level cognitive control, and a segregation of the default mode network from task-related networks. These findings suggest that short-term task automatization is enabled by the brain's ability to rapidly reconfigure its large-scale network organization involving complementary integration and segregation processes.

Modular Segregation of Structural Brain Networks Supports the Development of Executive Function in Youth

“…Taken together, the current data suggest that structural brain networks re-configure with age, becoming both more modular and more globally integrated. This specific topology may allow for both functional specialization within modules as well as coordination across modules, which is necessary for effective implementation of dynamic executive processes [44,50–52]. …”

Dynamic reconfiguration of functional brain networks during working memory training

“…For example, Bassett et al (2015) showed that training on a visuomotor task over the course of 6 weeks leads to increased autonomy between task-relevant subnetworks in motor and visual cortices. In another study, Mohr et al (2016) found increased segregation of the default mode system after short-term visuomotor training. Collectively, these findings suggest that an increase in network segregation and a decrease in integration may constitute a natural consequence of task automation.…”

“…The brain constantly adjusts its architecture to meet the demands of the ever-changing environment. Such neural adaptation spans multiple time scales, being observed over seconds to minutes during task performance (Braun et al, 2015;Vatansever et al, 2015;Cohen and D'Esposito, 2016;Shine et al, 2016;Finc et al, 2017), over days to weeks during learning (Bassett et al, 2013Mohr et al, 2016), and over years during development (Betzel et al, 2014). Like many other com-plex biological systems, the adaptability of the brain is supported by its modular structure (Friston, 2009;Sporns, 2013).…”

“…In the present study, we investigated whether mastering a demanding working memory task affects the balance between network segregation and integration during task performance. Does effortless performance of the demanding cognitive task lead to the same increase in network segregation that is characteristic of simple motor tasks (Cohen and D'Esposito, 2016;Mohr et al, 2016)? Is the breakdown of network segregation during the changing demands of the cognitive task still necessary when the cognitive task is automated?…”

The task novelty paradox: Flexible control of inflexible neural pathways during rapid instructed task learning

“…So far, only a small number (Cole et al, 2013b; Mohr et al, 2016) have investigated task-evoked functional connectivity effects, which are of primary interest here. Mohr et al (2016) used a simple stimulus-response paradigm similar to the NEXT paradigm but did not focus on task-evoked functional connectivity between control systems and their effects on stimulus-motor representations. Cole et al (2013) focused on distributed representations between the frontoparietal control system and other systems, but used the complex PRO paradigm and did not isolate stimulus-motor representations.…”