Neural Correlates of Working Memory: Socioeconomic Disparities within Executive Function and the Role of Cognitive Stimulation

Previous studies have found early life socioeconomic status to be associated with executive function performance. Children from families of higher socioeconomic status tend to have better executive function, both early in life and beyond, as compared to peers from families of lower socioeconomic status. This study aims to explore potential factors that could explain this association, specifically focusing on the role of cognitive stimulation and neural function in regions of the brain within the dorsal attention network and the ventral visual stream. At the first time point of this study, 75 children aged 5 and 6 years completed a N-Back fMRI working memory task and received executive function assessments. At the second time point, 33 children, now aged 7 to 10 years, completed further executive function performance testing. We re-established the association between higher early childhood socioeconomic status and better performance on executive function tasks, both at the initial time point and also longitudinally. Furthermore, early childhood socioeconomic status was also found to be associated with higher levels of cognitive stimulation in the home environment. However, there were no significant findings showcasing the association between cognitive stimulation and executive function performance. Though, the results showed positive trends in the same direction as prior studies that have found significance within this association. Moreover, we also found significant activation within the Fusiform Gyrus and the Lateral Occipital Cortex in response. Surprisingly, parental education seemed to have a negative association with activation with the Fusiform Gyrus during facial processing, whereas income seemed to have a positive association with the Lateral Occipital Cortex during object processing. Unexpectedly, income, parental education and cognitive stimulation were not significantly associated with neural activity during the fMRI working memory task. Together, these findings emphasize the need for further research within this field to explore the full extent in which early childhood socioeconomic status affects executive functions and neural outcomes. By better understanding these mechanisms, we hope this research can ultimately inform interventions and advocate for better social systems to better support children and families from marginalized backgrounds.