Cognitive-Structural Decoupling in Long-Lived Bats: Quantifying Resilience Beyond Age and Global Brain Structure

Abstract: Long-lived species such as bats maintain remarkable cognitive function despite advanced biological age, suggesting a potential decoupling between biological aging, brain structural integrity, and cognitive performance. To investigate this phenomenon in the Egyptian fruit bat (Rousettus aegyptiacus), we integrated multi-modal data from 30 individuals, including DNA methylation age, cognitive performance on a foraging task, and global Diffusion Tensor Imaging (DTI) metrics. We quantified cognitive flexibility using a novel metric, the Cognitive Adaptation Efficiency (CAE), derived from perseverative errors in short- and long-term memory phases. To assess individual resilience, we developed a Cognitive-Structural Decoupling Index (CSDI), calculated as the residuals from a multiple linear regression model predicting CAE based on DNA methylation age, sex, and global DTI metrics (Fractional Anisotropy and Mean Diffusivity). Our findings revealed substantial inter-individual variability in CAE, but critically, no significant age-related decline in cognitive flexibility. Furthermore, the predictive model for CAE was not statistically significant and explained minimal variance, providing direct evidence for a decoupling between cognitive performance, biological age, and global brain structural integrity in this species. The CSDI successfully quantified individual cognitive resilience, indicating performance better than expected given a bat's age and global brain measures. These results underscore that in long-lived mammals, the relationship between aging, global brain structure, and cognition is not straightforward, highlighting the importance of exploring specific compensatory mechanisms that confer resistance to age-related cognitive decline.

Subjects:	q-bio.NC; q-bio.QM
Cite as:	PX:2508.00039