Social and Motivational Processing in Middle Age and Older Adults

Compared to cognition, the processing of social cues and their subsequent impact on motivation is not well understood in middle age and older adulthood. This is problematic because many age-related neurobiological disorders like Alzheimer’s Disease and related dementias (ADRD) are also characterized by social and motivational deficits. It is unclear if these social and motivational deficits are a result of the disease, or if social and motivational deficits contribute to the development of these diseases. The central hypothesis of this proposal is that social incentives engage social, motivational, and cognitive brain networks, and this network engagement ultimately leads to improved cognition in later life. This hypothesis will be tested by pursuing three specific aims: 1) Determine if there are age-related differences in affective responses to monetary and social incentives; 2) Determine if there are age-related differences in affective responses to socially salient (friend) compared to socially unimportant (stranger) incentives; and 3) Identify how social and motivational processing are related to global cognitive function in middle age and older adults. Using well-established tasks and measures, we will investigate subjective, psychophysiological, and neural responses during anticipation of social and monetary incentives (Aims 1 & 2), and the relationship between these affective responses and cognitive function (Aim 3) in one study of middle age and early older adults (ages 35-75). In Session 1, the participant will complete cognitive testing while their designated social partner completes a facial expression photography session. Between Sessions 1 and 2, participants will complete a 14-day period of ecological momentary assessment to measure their social engagement in everyday life. During that time, the social partner’s pictures that best represent each emotional expression (e.g. happiness, anger) will be validated and used to create dynamic stimuli (e.g. changing from a neutral expression into a smile) for use in later sessions. In Session 2, experimenters will record skin conductance response while participants report their subjective affective experience during Monetary Incentive Delay and two variants of the Social Incentive Delay tasks, one featuring social incentives (smiles or frowns) from their social partner (friend) and another featuring incentives from a stranger. In Session 3, a subset of participants will complete the same tasks while undergoing fMRI. The study is innovative because it combines theories and techniques from psychology and neuroscience to better understand motivation, both in the lab and in situ, in the oft-neglected population of middle age. It also focuses on the inclusion of underrepresented populations, particularly African American/Black and Hispanic/Latiné, and proposes contributing to a growing data base of racially- and age-diverse facial stimuli for use in the broader research community. This project will generate critical insight about under-studied aspects of aging that will guide the development of interventions to improve cognition in later life, and potentially stave off the impact of debilitating age-related diseases like Alzheimer’s disease.