Age-related alterations in default mode network: Impact on working memory performance
Fabio Sambataro, Vishnu P. Murty, Joseph H. Callicott, Hao-Yang Tan, Saumitra Das, Daniel R. Weinberger, Venkata S. Mattay
Neurobiology of Aging August 1, 2008 DOI: 10.1016/j.neurobiolaging.2008.05.022 via OpenAlex
Summary
AI-generated from the abstractNormal aging reduces the ability to suppress low-frequency oscillations and decreases functional connectivity within the default mode network (DMN) during a working memory task. Older adults showed weaker coupling between the posterior cingulate and medial prefrontal cortex, and this coupling strength correlated positively with performance. The posterior cingulate was also negatively coupled with task-related regions like the dorsolateral prefrontal cortex and cingulate. These changes may reflect a deficit in cognitive control that impairs resource allocation to the task.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | Older and younger adults |
| Citations | 534 |
| Key finding | Older adults showed decreased DMN connectivity and ability to suppress low-frequency oscillations during a working memory task, with weaker posterior cingulate-medial prefrontal cortex coupling linked to lower performance. |
Abstract
The default mode network (DMN) is a set of functionally connected brain regions which shows deactivation (task-induced deactivation, TID) during a cognitive task. Evidence shows an age-related decline in task-load-related modulation of the activity within the DMN during cognitive tasks. However, the effect of age on the functional coupling within the DMN and their relation to cognitive performance has hitherto been unexplored. Using functional magnetic resonance imaging, we investigated functional connectivity within the DMN in older and younger subjects during a working memory task with increasing task load. Older adults showed decreased connectivity and ability to suppress low frequency oscillations of the DMN. Additionally, the strength of the functional coupling of posterior cingulate (pCC) with medial prefrontal cortex (PFC) correlated positively with performance and was lower in older adults. pCC was also negatively coupled with task-related regions, namely the dorsolateral PFC and cingulate regions. Our results show that in addition to changes in canonical task-related brain regions, normal aging is also associated with alterations in the activity and connectivity of brain regions within the DMN. These changes may be a reflection of a deficit in cognitive control associated with advancing age that results in deficient resource allocation to the task at hand.