Social engagement intervention increases dorsal attention network functional connectivity in socially‐isolated older‐old adults: I‐CONECT

Abstract

AbstractBackgroundSocial engagement represents a promising intervention to improve or maintain cognitive function, however the neurobiological mechanism through which social engagement impacts cognitive aging remains unclear. Large‐scale cognitive brain networks facilitate cognitive function and represent a set of likely candidates for being affected by social engagement interventions.Using resting‐state functional magnetic resonance imaging (rs‐fMRI) data from the Internet‐Based Conversational Engagement Clinical Trial (I‐CONECT), we investigated the effect of social engagement intervention on functional connectivity within large‐scale cognitive brain networks, specifically the default mode network (DMN), salience network (SAL), frontoparietal network (FPN), and dorsal attention network (DAN).MethodDue to COVID‐19 pandemic, out of 186 randomized participants in the trial, 15 participants were able to complete rs‐fMRI both at baseline and six‐month follow‐up: six participants from the intervention arm (five women; mean age±SD: 79.0±3.8 years) and nine participants from the control arm (six women; 81.2±5.2 years). Nine participants had mild cognitive impairment; six had normal cognition.Intervention effect was calculated in separate regression models for within‐network connectivity of each brain network, with intervention group predicting connectivity at six‐month follow‐up, controlling for baseline connectivity, age, sex, site, and in‐scanner motion.ResultIn examining the intervention effect on DAN connectivity, the overall regression model was statistically significant (R2= 0.867, p = 0.004; Table 1): The experimental group had significantly higher DAN connectivity at follow‐up (b = 0.25, 95% CI: 0.03 – 0.47, p = 0.031) compared with the control group, (for group x time graph using residualized connectivity values, see Figure 1). Overall regression models for DMN, SAL, and FPN networks were not statistically significant (p > 0.1).ConclusionAs social engagement interventions emerge as an effective approach to improving cognition in older adults, this work provides novel insight into the impact of such an intervention on large‐scale cognitive brain network connectivity. Specifically, participants who underwent the intervention showed greater DAN connectivity at follow‐up than control participants. The voluntary directed attention facilitated by the DAN is an integral part of social engagement, and this work suggests that DAN merits additional focus in investigations of social behavior in cognitive aging. These findings must be interpreted with caution, due to small sample size.