Cognitive reserve moderates the association between functional network anti-correlations and memory in MCI

Area of Science:

• Neuroscience
• Cognitive Psychology
• Medical Imaging

Background:

• Cognitive reserve (CR) is known to protect cognitive function in aging.
• The impact of CR on functional brain networks in mild cognitive impairment (MCI) requires further investigation.
• Understanding network dynamics is crucial for identifying protective mechanisms against cognitive decline.

Purpose of the Study:

• To investigate the moderating role of cognitive reserve (CR) on the relationship between functional network connectivity and memory performance in amnestic mild cognitive impairment (aMCI).
• To examine the association between internetwork cross-talk, specifically the default mode network (DMN) and dorsal attention network (DAN), and memory deficits in aMCI.
• To determine if proxies of CR, such as education and intelligence (IQ), alleviate the negative impact of reduced network anti-correlation on memory.

Main Methods:

• Resting-state functional magnetic resonance imaging (fMRI) with sliding time window analysis was used to assess DMN-DAN anti-correlation in aMCI patients and healthy controls (HC).
• CR was measured using years of education and intelligence (IQ) scores.
• Statistical analyses were performed to evaluate the association between DMN-DAN anti-correlation, memory performance, and CR in independent aMCI cohorts.

Main Results:

• While DMN-DAN anti-correlation was numerically lower in aMCI compared to HC, the difference was not statistically significant.
• In aMCI patients, reduced anterior DMN-DAN anti-correlation was significantly associated with poorer memory performance.
• Higher levels of education and IQ (CR proxies) were found to moderate this association, alleviating the negative impact of decreased network anti-correlation on memory.

Conclusions:

• Reduced functional connectivity between the dorsal attention network and default mode network is linked to memory impairment in amnestic mild cognitive impairment.
• Cognitive reserve, indicated by education and IQ, plays a crucial buffering role, mitigating the detrimental effects of impaired network cross-talk on memory in aMCI.
• These findings highlight the importance of functional network analysis and cognitive reserve in understanding and potentially preserving cognitive function in aging and MCI.