The Impact of Aging on the Neural and Behavioral Bases of Empathy

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Project Summary/Abstract: Research Project (C) By 2060, adults 65 years of age and older are predicted to make up 24% of the U.S. population. Therefore, factors that impact older adults’ cognitive and emotional health are of significant concern. Of particular importance are age-related declines in specific subtypes of empathy. These declines greatly impact public health because reduced empathy has been associated with numerous mental health conditions, including increased depression and loneliness. It is important to note that reduced empathy not only affects healthy older adults, but also appears to be selectively affected in specific age-related neurological disorders such as fronto- temporal dementia and Alzheimer’s disease. Therefore, characterizing the mechanisms underlying age-related declines in the subtypes of empathy could provide key information to develop targeted interventions that could have a major impact on aging-related diseases, as well as the many other patient populations affected by low empathy (e.g., autism, schizophrenia, traumatic brain injury). Current research suggests that there are two subtypes of empathy (i.e., cognitive and emotional) and that healthy older adults show significant declines in the cognitive subtype of empathy (i.e., understanding others’ thoughts and feelings), with preserved or enhanced function in the emotional subtype (i.e., feeling compassion for others). These declines in cognitive empathy have been linked to neural changes in regions associated with thinking about others’ mental states, such as the dorsomedial prefrontal cortex. Moreover, there is evidence suggesting that declines in cognitive empathy may be at least partially attributable to age-related deficits in other cognitive functions, such as executive function and memory. However, little is known on the neural bases of preserved emotional empathy in older adults, and the trajectory of neural and behavioral function underlying each empathy subtype has never been examined across the adult lifespan. Furthermore, while previous studies have focused on relationships with chronological age, they have not measured the link to biological age, which has been shown to be a more accurate marker of the physiological impacts of lifespan stressors and is predictive of disease risk and all-cause mortality. To address these gaps in knowledge, this proposal will investigate the trajectory of age-related changes in the cognitive and emotional subtypes of empathy through behavioral and functional neuroimaging methods. Participants will include 116 healthy adults ranging in age from 25-75 years of age. Gold standard cognitive and emotional empathy tasks will be used to probe age- related behavioral changes, and functional MRI will be used to assess neural changes, in both intrinsic networks and task-based activation during empathy tasks. Aging will be assessed using both chronological and biological aging (based on DNA methylation) metrics to provide a more precise quantification of the aging process. The results of this proposal will lay the groundwork for the development of interventions designed to target specific subtypes of empathy, with widespread implications for the clinical populations experiencing reduced empathy.