Associations between subjective cognitive concern, brain network connectivity, and cognitive performance in cognitively normal older adults

Subjective Cognitive Decline (SCD) is the perception of a persistent decline in cognitive function and self-reported concerns over cognitive ability in older adults with normal objective cognitive performance. SCD is associated with increased Alzheimer's Disease (AD) risk and early AD pathology. The neurobiological underpinnings of SCD and cognitive or neural circuit alterations during SCD remain unclear. This study aimed to identify patterns of brain network functional connectivity that are associated with quantitative measures of cognitive concerns, and to examine how these functional patterns are related to performance in the cognitive domains of visual-spatial processing, attentional control, and working memory. This analysis combined data from three studies of cognitively healthy older adults which included a quantified assessment of cognitive concern severity, resting-state fMRI, and cognitive testing in the above domains. We examined brain network-to-network functional connectivity associated with self-rated cognitive concern severity, and then how the identified patterns relate to cognitive performance. Results showed that greater cognitive concern severity was associated with unique patterns of functional connectivity between the Default Mode Network and the Language and Salience Networks in older adults without objective cognitive impairment. While greater cognitive concern severity alone was associated with slower processing reaction time, these functional connectivity patterns were associated with faster processing reaction time. This suggests that these functional connectivity patterns may alter the relationship between cognitive concern severity and psychomotor slowing. These findings support that despite the perception of cognitive changes in older adults, normal cognitive performance may be maintained through functional connectivity changes in brain networks important to directing visual-spatial attention and processing.