One Size (Brain Development) Does Not Fit All
Monica Ellwood-Lowe (PhD candidate in Psychology, UC Berkeley) shares results from two neuroscience studies about patterns of brain activity for children from different socioeconomic backgrounds, supported by CEGA’s Psychology and Economics of Poverty Initiative and the UC Berkeley Institute of Cognitive and Brain Sciences. For more information abou this work, please see our related publications and our presentation from the 2022 Psychology and Economics of Poverty Convening.
The development of cognitive skills is critical for academic success and economic outcomes. Decades of psychological and economic science point to the detriments of growing up in poverty, particularly for children’s cognitive and academic performance. But there is massive variability in outcomes for children in poverty — many of whom perform quite well. How do high-performing children in poverty achieve this resilience in the face of structural barriers to success? Neuroscience can help shed light on whether children achieve high performance through the same underlying brain mechanisms as children not in poverty.
Exploring brain patterns and academic resilience among children
Along with senior author Silvia Bunge (UC Berkeley) and coauthors Susan Whitfield-Gabrieli (Northeastern University) and Carolyn Irving (UC Berkeley), we drew from a dataset of nearly 10,000 children in the United States to find that high performance for children in poverty is not associated with the same brain activation patterns as high performance for children not in poverty. We considered children to be living below the poverty line if they were living in a household of 4 with a total income of less than $25,000, or a household of 5 or more with a total income of less than $35,000 (for more information, see Ellwood-Lowe et al., 2021)
To study children’s brain activity, we used a subsample dataset of 1,115 children between ages 9–10 living in poverty from the national ABCD Study, one of the largest and longest-term studies of brain development and child health to date. We analyzed functional Magnetic Resonance Imaging (fMRI) brain scans from this subsample, measuring brain activity when children were resting in the scanner. This method helps us understand how different brain networks work in synchrony with one another — or communicate with each other — in children’s day-to-day lives, providing a tool for measuring children’s recent thought patterns. We used these measures of children’s brains at rest at age 10, and examined their association with cognitive and academic performance at ages 10 and 12. We looked specifically at a pattern of resting brain activity previously associated with high performance — less communication between brain regions that underlie performance of demanding external tasks (e.g., taking a test) and those that underlie internally-directed thoughts (e.g., thinking about things outside of the here and now). This functional separation is thought to be adaptive, as it may allow children to tune out distracting internal thoughts while focusing on external tasks.
Evidence that “optimal” brain development depends on childrens’ environment
As prior research would suggest, we found that less communication between the brain regions underlying externally- and internally-directed thoughts was associated with high cognitive performance — but this was only true for higher-income children. For children living in poverty at age 10, the opposite pattern emerged: more communication between these brain regions was actually associated with higher performance. This association was present for children’s performance on standardized measures of cognition, their grades in school, and their attention problems.
Contradicting prior understanding of higher cognition, these results suggest that for children living in poverty, it is adaptive for the system involved in external thought to work in tandem with the system involved in internal thought. This dissociation may be caused by children’s adaptations to structural features of their environments, such as their schools and neighborhood safety. For example, in environments where there is more immediate danger, children may have to more frequently engage in thought patterns that require internal and external thought simultaneously, such as monitoring their own reactions closely while engaging in complex reasoning about the situation they are encountering. Their ability to successfully navigate these environments may set them up to perform highly on cognitive tests. While future research is needed to understand this mechanism more clearly, our findings reveal that children in poverty might rely on different mechanisms to perform well, suggesting there is no one, normative way to develop in all circumstances.
