Frontopolar Cortex and Motivation in Healthy Older Adults

Motivation represents a core aspect of goal-directed behavior as it determines how much effort individuals are willing to invest to reach their goals. While research on effort-based decision-making focuses mainly on effort preferences in younger adults, loss of motivation might be a key component of the apathetic tendencies frequently seen in older adults. However, an open question refers to which brain mechanisms underlie motivational processes in older adults. The investigators have recently shown that the frontopolar cortex plays a crucial in motivating the exertion of rewarded effort in younger adults (Soutschek et al., 2018, Biological Psychiatry). The goal of the current study is to determine whether frontopolar cortex plays a crucial role for motivation also in older adults and may thus be a promising target for improving the motivation deficits in healthy aging. 30 older participants (65-80 years) perform computer-based experimental tasks measuring the propensity to exert cognitive or physical effort for monetary rewards. During task performance, participants receive 1 mA anodal or sham transcranial direct current stimulation (tDCS) over their frontopolar cortex. The study tests whether tDCS over frontopolar cortex allows modulating participants' motivation to engage in rewarded effort.