Abstract
Vulnerability to fraud and financial exploitation among older adults is an increasing public health concern. Growing evidence supports that cognitive and socioemotional changes with age contribute to greater exploitation risk among older adults, while the neural mechanisms of heightened susceptibility to deception in aging are not well understood. Of note, white matter tracts are particularly impacted in aging and are likely implicated in deception detection. This study, for the first time, examined the extent to which age-related differences in white matter pathways subserving social cognition mediated susceptibility to email phishing, a potent, fast-evolving Internet deception threat. Fifty-one younger (21.82 ± 3.47 years) and 46 cognitively healthy older (68.87 ± 6.56 years) adults underwent diffusion-weighted imaging and completed the ecologically-valid PHishing Internet Task (PHIT), which provides a behavioral measure of real-life susceptibility to email phishing. Deterministic tractography-generated a priori tracts of interest included the cingulum, uncinate fasciculus (UF), anterior thalamic radiation (ATR), and superior longitudinal fasciculus-collectively referred to as "social white matter." White matter integrity metrics (i.e., mean diffusivity [MD] and fractional anisotropy [FA]) were extracted from these tracts. Regression-based mediation analyses controlling for sex, education, general cognition, and global MD and FA (separately) showed that both increased right ATR MD and decreased left UF FA partially mediated the effects of age group on phishing susceptibility (higher PHIT scores with greater age). These findings advance a social white matter-based account of age-related exploitation risk, shedding light on the neurobiology underlying social decision-making deficits in aging.