Age differences in the frontoparietal cognitive control network: Implications for distractibility

Abstract

Current evidence suggests that older adults have reduced suppression of, and greater implicit memory for, distracting stimuli, due to age-related declines in frontal-based control mechanisms. In this study, we used fMRI to examine age differences in the neural underpinnings of attentional control and their relationship to differences in distractibility and subsequent memory for distraction. Older and younger adults were shown a rapid stream of words or nonwords superimposed on objects and performed a 1-back task on either the letters or the objects, while ignoring the other modality. Older adults were more distracted than younger adults by the overlapping words during the 1-back task, and they subsequently showed more priming for these words on an implicit memory task. A multivariate analysis of the imaging data revealed a set of regions, including the rostral PFC and inferior parietal cortex, that younger adults activated to a greater extent than older adults during the ignore-words condition, and activity in this set of regions was negatively correlated with priming for the distracting words. Functional connectivity analyses using right and left rostral PFC seeds revealed a network of putative control regions, including bilateral parietal cortex, connected to the frontal seeds at rest. Older adults showed reduced functional connectivity within this frontoparietal network, suggesting that their greater distractibility may be due to decreased activity and coherence within a cognitive control network that normally acts to reduce interference from distraction.

Age differences in brain activity related to unsuccessful declarative memory retrieval

“…However, most of these earlier studies examined resting-state functional connectivity, and it is unclear whether similar age reductions would be found during our tasks, on which there were no age differences in overall accuracy or response times (St-Laurent et al, 2011). Previous work also has shown age-related reductions in connectivity between areas from the frontoparietal control network, or FPC (Spreng et al, 2013;Vincent et al, 2008) and SLN areas, such as the aIFO (Campbell et al, 2012;He et al, 2013). Thus, we anticipated that age differences might emerge in the strength of functional connections between SLN nodes and other brain regions, particularly those involved in cognitive control.…”

“…It also is interesting that the aIFO seeds were functionally connected to cognitive-control regions, such as frontal and parietal areas thought to be nodes of the frontoparietal control network, as well as with other SLN regions. Prior work focusing on either the SLN or the FPC have identified aIFO as a participant in both of these networks (Campbell et al, 2012;Spreng et al, 2013;Vincent et al, 2008), indicating that aIFO activity may reflect the engagement of either of these two networks.…”

“…It also is interesting that the aIFO seeds were functionally connected to cognitive-control regions, such as frontal and parietal areas thought to be nodes of the frontoparietal control network, as well as with other SLN regions. Prior work focusing on either the SLN or the FPC have identified aIFO as a participant in both of these networks (Campbell et al, 2012;Spreng et al, 2013;Vincent et al, 2008), indicating that aIFO activity may reflect the engagement of either of these two networks.In addition to the main patterns of functional connectivity within the SLN, we also found that the aIFO seeds were functionally coupled with other regions during the retrieval conditions, and these patterns of connectivity were specific to the type of memory content that participants were attempting to retrieve, but only in the young adults. In the young group, the aIFO seeds were functionally connected to ventromedial PFC and a region in the dorsal superior frontal gyrus during AM errors.…”

Thalamic functional connectivity and its association with behavioral performance in older age

“…In older adults, increased activity (Buckner, 2004; Cabeza, Anderson, Locantore, & McIntosh, 2002; Reuter‐Lorenz et al., 2000) or connectivity (Campbell, Grady, Ng, & Hasher, 2012; Davis, Dennis, Daselaar, Fleck, & Cabeza, 2008; Geerligs, Maurits, Renken, & Lorist, 2014) is often considered to be compensatory in nature. The recruitment of additional brain regions or increased connectivity between brain regions has been suggested to support the maintenance of cognitive function which would otherwise be disrupted due to age‐related brain changes, such as loss of gray matter or reductions in within‐network connectivity.…”

Competition between frontoparietal control and default networks supports social working memory and empathy

“…The top-down control function of the FPC allows for focusing attention on goal-relevant information and suppressing goal-irrelevant information (Smallwood et al, 2012;Wen et al, 2013). Declines in frontoparietal control mechanisms may result in greater distractibility (Campbell et al, 2012).…”