Grant: Project Grant

Children of lower socioeconomic status (SES) underperform relative to their higher SES peers on cognitive tasks by up to a whole standard deviation by the time they begin elementary school, with gaps persisting into adolescence and beyond. Despite these oft-emphasized negative consequences, one emerging theory suggests that early life experience in lower SES conditions may in fact counterintuitively accelerate brain development: Greater prevalence of stress in lower-income homes may program a shorter childhood, speeding maturation of key brain regions including those involved in learning and memory. Yet, reports of cognitive advantages for lower SES children are scarce, raising doubts about acceleration. Our key to addressing this gap lies in our theoretically motivated consideration of anterior hippocampus (aHC), a region especially vulnerable to stress. We have curated a set of functional, behavioural, and structural measures linked to aHC, which we will use to assess how SES influences the pace of children's memory development. Our preliminary data using such a task show that, remarkably, lower SES children indeed perform similarly to adults and better than their higher SES counterparts when they form memories in a mature, aHC-dependent way. Here, we will extend upon these findings to test the core prediction that this behavioural benefit reflects accelerated maturation of aHC function triggered by early lower SES. Our novel approach combining tailored measures of function, behaviour, and structure with longitudinal assessment will also enable us to directly link accelerated maturation to its potential negative consequences, posited to include compromised structure or worse mental health in adolescence and/or adulthood. As such, this work will offer crucial insights for health-related research, given altered hippocampal processing has been implicated in certain psychiatric disorders (e.g., depression, schizophrenia) that are more common among lower SES people.