Edge-Community Entropy Is a Novel Neural Correlate of Aging and Moderator of Fluid Cognition.

Decreased neuronal specificity of the brain in response to cognitive demands (i.e., neural dedifferentiation) has been implicated in age-related cognitive decline. Investigations into functional connectivity analogs of these processes have focused primarily on measuring segregation of nonoverlapping networks at rest. Here, we used an edge-centric network approach to derive entropy, a measure of specialization, from spatially overlapping communities during cognitive task fMRI. Using Human Connectome Project Lifespan data (713 participants, 36-100 years old, 55.7% female), we characterized a pattern of nodal despecialization differentially affecting the medial temporal lobe and limbic, visual, and subcortical systems. At the whole-brain level, global entropy moderated declines in fluid cognition across the lifespan and uniquely covaried with age when controlling for the network segregation metric modularity. Importantly, relationships between both metrics (entropy and modularity) and fluid cognition were age dependent, although entropy's relationship with cognition was specific to older adults. These results suggest entropy is a potentially important metric for examining how neurological processes in aging affect functional specialization at the nodal, network, and whole-brain level.

Trait mindfulness and emotion regulation responsiveness to negative affect in daily life.

Objectives: Recent conceptualizations of adaptive emotion regulation is predicated on the ability to flexibly use emotion regulation strategies to meet changing contextual demands. Although trait mindfulness has been linked to enhanced emotional well-being and use of adaptive emotion regulation strategies, there is a dearth of literature examining associations between trait mindfulness and emotion regulation flexibility. Further, despite a rich literature suggesting that emotion regulation processes change with age, no study to date has assessed whether the role of trait mindfulness on emotion regulation responsiveness to negative emotions-a component of emotion regulation flexibility-differs between young and older adults. Methods: The current study recruited 130 young adults and 130 older adults to assess trait mindfulness, emotion regulation strategy use, and emotion regulation responsiveness of six distinct strategies in daily life. Results: Across the full sample, trait mindfulness was related to reduced distraction (ß = -0.11, t(238.09) = -3.02, p = .003) and expressive suppression (ß = -0.15, t(237.70) = -4.62, p < .001) strategy use. Age moderation analyses revealed that trait mindfulness was associated with reduced expressive suppression responsiveness (ß = 0.12, t(247) = 2.31, p = .022) in young adults and increased detached reappraisal responsiveness among older adults (ß = 0.15, t(247) = -2.95, p = .003). Conclusions: The current findings highlight the importance of understanding how trait mindfulness is associated with strategy use and responsiveness to negative affect changes in daily life as well as how these patterns may shift across the lifespan. Manuscript Pre-registration: Open Science Framework, registration number: z5g8v.