Researchers have found that childhood poverty can lead to lasting changes in the way the brain processes language. Even in adults who perform well in language tasks, those who experienced poverty as children showed different neural activity patterns compared to their middle-income peers. The study, published in Brain and Language, highlights the long-term impact of early socioeconomic conditions on brain function, suggesting that the chronic stress associated with poverty might alter neural pathways involved in language processing.
Previous studies have established that children from low-income backgrounds often exhibit deficits in language skills, such as vocabulary, grammar, and reading. These deficits can have significant implications for academic and career success later in life. However, it was unclear whether these language deficits persisted into adulthood and how they manifested in brain activity. The new study aimed to fill that gap by examining the neural correlates of language processing in adults who grew up in poverty.
“When I was a special education teacher of youth from high-risk backgrounds, I became interested in how poverty and other contextual childhood experiences, such as childhood maltreatment and other traumatic experiences, influence cognitive development,” explained study author Suzanne Perkins, a research investigator in the Research Center for Group Dynamics at the Institute for Social Research at The University of Michigan
“I noticed that children and adolescents with multi-exposure backgrounds were particularly struggling academically. This was long before people were talking about trauma-informed education. I saw students from trauma-based backgrounds, who were otherwise bright, engaged, and studious, contend with competing cognitive demands which made the successful completion of tasks more challenging than for youth without such complex backgrounds.”
The study was a longitudinal follow-up to a larger research project that tracked the development of children from different socioeconomic backgrounds. Participants were drawn from an existing cohort that included families with incomes below the U.S. poverty line and middle-income families. The study followed one child and one parent from each family through multiple waves of data collection, starting at age 9 and continuing until age 24.
At age 24, a subsample of 54 participants (24 from the poverty group and 27 from the middle-income group) were recruited for a brain imaging study at the University of Michigan. Participants underwent a series of language processing tasks while their brain activity was monitored using functional magnetic resonance imaging (fMRI). These tasks included phonemic decoding, reading recognition, reading comprehension, and receptive vocabulary assessments, as well as an event-related task involving the processing of printed and spoken words.
“Childhood poverty is a common and preventable potential challenge to brain development,” Perkins told PsyPost. “We know that children who grow up in low-income-to-needs circumstances often have less educated parents, more limited access to the building blocks of brain health like books and nutritious foods, fewer high-quality early childhood educational opportunities, and attend lower-performing public schools. All this results in lower academic achievement and educational and career outcomes in adulthood.”
“Most adults function well day-to-day, in reading and other uses of language. Most people can read signs, menus, job applications, and on-the-job materials, and can communicate effectively with co-workers and other people in their lives. We wondered to what extent adults who grew up in poverty may have differences in how the brain processes novel phonemes, which might make taking on advanced schooling or new job challenges seem daunting.”
Although both groups performed within the average range on behavioral language tests, the poverty group consistently scored lower on phonemic decoding and reading recognition tasks. This suggests that early childhood poverty has a lasting impact on specific language skills, even if overall language performance appears average.
Phonemic decoding is the ability to understand and manipulate the individual sounds (phonemes) that make up words. It involves recognizing the relationship between letters and sounds to read words correctly, especially unfamiliar or made-up words (pseudowords). Reading recognition, on the other hand, is the ability to identify and understand written words quickly and accurately, often through visual memory of word shapes and patterns. It includes recognizing common words on sight without needing to sound them out.
Brain imaging results showed that adults from middle-income backgrounds exhibited greater activation in the left inferior frontal gyrus (IFG) and other regions typically associated with language processing, such as Broca’s area and Wernicke’s area. These areas are crucial for tasks like phonemic decoding and reading comprehension, indicating that middle-income participants utilized the standard neural pathways for language processing.
In contrast, adults who grew up in poverty showed less activation in these traditional language regions but exhibited greater activation in compensatory areas, such as the right IFG and the visual word form area (VWFA). The increased activity in these regions suggests that individuals from the poverty group rely on alternative neural pathways to achieve similar language performance levels as their middle-income counterparts. This reliance on different brain regions is indicative of neural plasticity, where the brain adapts to early environmental challenges by developing new strategies for processing language.
These findings underscore the notion that the brain’s development is significantly influenced by early socioeconomic conditions. The neural adaptations observed in the poverty group reflect the brain’s capacity to compensate for the adverse effects of childhood poverty. This compensation may allow individuals to perform adequately in language tasks despite underlying differences in neural activity.
The study also highlights the importance of educational attainment in mitigating the impact of childhood poverty on language processing. While current income did not significantly affect language functioning, higher educational attainment was associated with better language performance. This suggests that continued education can help offset some of the negative effects of early poverty, providing a pathway for improved language skills and cognitive development.
“We found that adults from childhood poverty had atypical use of brain pathways while reading novel nonwords, which everyone has to sound out,” Perkins explained. “This was true even after accounting for overall task behavioral performance, which was not much different between groups. This suggests that aspects of poverty, which we did not measure, such as poor schooling, fewer books, and worse nutrition, may influence how the brain learns to process new words and that altered processing lasts into adulthood. These altered ways of processing novel words in the environment may lead adults from low-income backgrounds to avoid challenging linguistic environments, including advanced schooling and career training. ”
“It is evidence that childhood poverty is a less-than-ideal developmental context. One policy implication is that we must address and eradicate childhood poverty, which we have the means in the United States to do. For adults who grew up in poverty, this work should not be seen as a condemnation of current functioning around language. The brain is highly plastic, and we found that adults from high-poverty backgrounds process language somewhat differently, but that should not preclude any adult language development or linguistic challenge.
“I would argue that our work suggests that adults who are shy or lack confidence in their language abilities can thrive in new language settings, such as advanced schooling, and that any actual deficits in production or comprehension can be remediated.”
While the study provides valuable insights into the long-term effects of childhood poverty on brain function, it also has limitations. The sample size was relatively small, and the participants were predominantly Caucasian, which may limit the generalizability of the findings to other racial and ethnic groups. Additionally, the study focused on individuals who were right-handed, healthy, and unmedicated, which may not reflect the broader population of adults who experienced poverty.
Future research could explore how different aspects of poverty, such as stress, nutrition, and educational opportunities, contribute to changes in brain function. It would also be beneficial to include a more diverse sample to examine whether these findings hold true across different demographic groups. Longitudinal studies that track brain development from childhood into adulthood could provide a more comprehensive understanding of how early experiences shape neural pathways.
“My long-term goals are to disentangle the cognitive outcomes of various traumatic exposures, including the chronic stress of poverty,” Perkins said. “I am interested in whether stressful life experiences could be a mechanism that leads to adaptations in how the brain processes novel phonemes. Understanding unique, competing, and combinatory cognitive processing differences can lead to the development of targeted interventions.”
The study, “Language processing following childhood poverty: Evidence for disrupted neural networks,” was authored by Suzanne C. Perkins, S. Shaun Ho, Gary W. Evans, Israel Liberzon, Meroona Gopang, and James E. Swain.
