Executive Functioning Markers of Functional Decline and Health Vulnerability in Older Adults: The Role of Temporal Discounting

Abstract

Temporal discounting (TD), a behavioral economic index of the tendency to devalue rewards or outcomes as delay to their receipt increases, captures future-oriented decision-making, self-control, and reward valuation. However, despite the well-documented predictive utility of TD in a variety of maladaptive health behaviors, psychopathology, and functional outcomes, the clinical utility of TD is understudied in neuropsychology, particularly in older adults at risk of or experiencing cognitive decline. This dissertation examined the role of TD in identifying early cognitive and behavioral vulnerability among older adults, with a focus on its utility relative to traditional executive functioning (EF) neuropsychological assessments. Specifically, in Study 1, TD was evaluated alongside standard EF measures to examine associations with functional status in instrumental activities of daily living (IADLs; e.g. cooking, managing finances) among individuals with and without mild cognitive impairment (MCI). Results showed that TD, in combination with working memory, significantly predicted IADL functioning but did not differentiate diagnostic status (i.e., MCI compared to normal cognition). TD also appeared to capture a distinct facet of EF, as it was not significantly correlated with other EF tasks. In Study 2, the relationship between TD, EF, and cumulative vulnerability burden (i.e., having multiple socioeconomic, behavioral, and health-related risk factors) was investigated. TD emerged as the sole cognitive correlate of high vulnerability status. Together, findings suggest that TD may reflect a shared neurobehavioral mechanism underlying both functional decline and health disparities in older adults. Overall, this research supports the integration of behavioral economic constructs in aging research and clinical assessment to improve early detection, intervention, and prognoses.