Socioeconomic status modulates cognition-achievement and brain-behavior relationships.

摘要

Socioeconomic status (SES) is associated with cognitive ability and achievement during childhood and beyond. However, little is known about the developmental relationships between SES and specific brain systems or their associated cognitive functions. Through the assessment of neurocognitive functioning in two separate cohorts of children from varied socioeconomic backgrounds, it was found that tasks that rely heavily on language processing skills are more highly correlated with SES than are tasks which tap other neurocognitive systems. Because of the exceptional importance of reading skill for academic and life achievement, the means by which SES influences that particular aspect of language development merited particular attention. It was found that SES can modulate cognition-achievement relationships in reading, such that phonological awareness (PA) is more highly associated with decoding among lower SES children, suggesting that greater access to resources may buffer reading skills among children with weaker PA. These results also suggest the possibility that a child who struggles with reading in the context of a lower SES environment might have difficulties that are fundamentally different from those of a child who struggles despite the access to resources typically associated with a higher SES environment. To investigate this possibility, neural activity associated with reading was examined across SES using functional magnetic resonance imaging (fMRI). Results demonstrated that lower SES children demonstrating a range of below-average PA exhibit the typically reported brain-behavior relationships, with higher PA associated with reading-related activity in left occipito-temporal and left perisylvian regions. In contrast, higher SES children with similar low skill levels show atypical brain-behavior relationships in these regions. Furthermore, higher SES children show positive correlations between PA and brain activity in putative compensatory regions, whereas lower SES children do not. It is thus concluded that socioeconomic background has the potential to modulate brain-behavior relationships in reading.