Prefrontal engagement and reduced default network suppression co-occur and are dynamically coupled in older adults: The default-executive coupling hypothesis of aging

摘要: Reduced executive control is a hallmark of neurocognitive aging. Poor modulation lateral pFC activity in the context increasing task challenge old adults and "failure to deactivate" default network during cognitive tasks have been observed. Whether these two patterns represent discrete mechanisms aging or interact into older adulthood remains unknown. We examined whether altered dynamics co-occur goal-directed planning over levels difficulty performance on Tower London task. used fMRI investigate task-and age-related changes brain activation functional connectivity across four challenge. Frontoparietal regions were activated suppressed relative counting both groups. Older adults, unlike young, failed modulate as demands increased. Critically, analyses revealed bilateral dorsolateral coupling young with increased complexity. propose default-executive hypothesis First, this suggests that failure response are linked adulthood. Second, involve greater increase adults. speculate reflect an adaptive shift approach come rely more upon stored representations support performance.