Grant: Project Grant

Every decision involves the choice to either exploit prior knowledge, towards a more predictable outcome; or to explore new sources of information, with less certain returns. This tension between exploitation and exploration is pervasive in everyday life. Do we return to the same vacation rental again next summer, or take that overseas trip? Do we watch our favourite cable news outlet or seek an alternative perspective? Do we rely on stereotypes or actively engage with unfamiliar others? We have shown that in young adults, decisions to explore versus exploit engage discrete brain regions. We have also hypothesized that an exploitation-bias emerges in later life, attributable to normal age-related brain and associated cognitive changes. Here we will directly test this exploitation-bias hypothesis using a series of decision-making tasks, combined with advanced structural and functional brain imaging, and blood-based biomarkers of Alzheimer's disease pathology. If our hypotheses are supported, the studies proposed here will provide the first evidence that this fundamental aspect of decision-making, arguably the starting point of all goal-directed thought and action, differs between younger and older adults. These discoveries will enhance our understanding of decision-making biases in later life, ultimately informing surveillance and intervention strategies to optimize function and sustain functional independence in older adulthood.