Modulation of Effective Connectivity in the Default Mode Network at Rest and During a Memory Task
Xingfeng Li, Elizabeth G. Kehoe, Thomas Martin McGinnity, Damien Coyle, Arun L.w. Bokde
Brain Connectivity February 1, 2015 DOI: 10.1089/brain.2014.0249 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational study Peer reviewed |
|---|---|
| Sample size | 28 |
| Population | Healthy older adults |
| Topics | Default mode network |
| Key findings | Effective connectivity within the default mode network differed between rest and an emotional face-name memory task, with the posterior cingulate cortex and hippocampus prominent at rest and additional amygdala and parahippocampal connections during the task. Connectivity from the posterior cingulate cortex, hippocampus, and amygdala correlated linearly with memory performance in both conditions, suggesting that superior memory ability in this older cohort was associated with effective connectivity of these memory-related regions. |
Abstract
It is known that the default mode network (DMN) may be modulated by a cognitive task and by performance level. Changes in the DMN have been examined by investigating resting-state activation levels, but there have been very few studies examining the modulation of effective connectivity of the DMN during a task in healthy older subjects. In this study, the authors examined how effective connectivity changed in the DMN between rest and during a memory task. The authors also investigated whether there was any relationship between effective connectivity modulation in the DMN and memory performance, to establish whether variations in cognitive performance are related to neural network effective connectivity, either at rest or during task performance. Twenty-eight healthy older participants underwent a resting-state functional magnetic resonance imaging scan and an emotional face–name encoding task. Effective connectivity analyses were performed on the DMN to examine the effective connectivity modulation in these two different conditions. During the resting state, there was strong self-influence in the regions of the DMN, while the main regions with statistically significant cross-regional effective connectivity were the posterior cingulate cortex (PCC) and the hippocampus (HP). During the memory task, the self-influence effective connectivites remained statistically significant across the DMN, and there were statistically significant effective connectivites from the PCC, HP, amygdala (AM), and parahippocampal region to other DMN regions. The authors found that effective connectivities from PCC, HP, and AM (in both resting state and during task) were linearly correlated to memory performance. The results suggest that superior memory ability in this older cohort was associated with effective connectity both at rest and during the memory task of three DMN regions, which are also known to be important for memory fuction.
Comparable studies
Other observational and cohort studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A default mode of brain function Normal adult human brain | 2001 | Observational study | |
| Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Healthy subjects | 2008 | Observational cohort | |
| Meditation experience is associated with increased cortical thickness Participants with extensive Insight meditation experience and matched controls | 2005 | Observational cohort | n = 20 |
| Meditation experience is associated with differences in default mode network activity and connectivity Experienced meditators and matched meditation-naive controls | 2011 | Observational cohort | |
| The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis Healthy subjects | 2008 | Observational study |