PAPER Associations between children’s socioeconomic status and prefrontal cortical thickness Gwendolyn M. Lawson, Jeffrey T. Duda, Brian B. Avants, Jue Wu and Martha J. Farah Department of Psychology, University of Pennsylvania, USA Abstract Childhood socioeconomic status (SES) predicts executive function performance and measures of prefrontal cortical function, but little is known about its anatomical correlates. Structural MRI and demographic data from a sample of 283 healthy children from the NIH MRI Studyof Normal Brain Development were used to investigate the relationship between SES and prefrontal cortical thickness. Specifically, we assessed the association between two principal measures of childhood SES, family income and parental education, and gray matter thickness in specific subregions of prefrontal cortex and on the asymmetry of these areas. After correcting for multiple comparisons and controlling for potentially confounding variables, parental education significantly predicted cortical thickness in the right anterior cingulate gyrus and left superior frontal gyrus. These results suggest that brain structure in frontal regions may provide a meaningful link between SES and cognitive function among healthy, typically developing children. Introduction Children who grow up in poverty tend to have lower IQs and academic achievement scores and are less likely to develop basic reading and mathematics proficiency than their higher-SES counterparts (Brooks-Gunn & Duncan, 1997; Gottfried, Gottfried, Bathurst, Guerin & Parra- more, 2003; Sirin, 2005). These outcome measures, while clinically meaningful, reflect the combined influence of many specific neurocognitive systems. It is these under- lying systems that mediate the association between SES and cognitive performance and provide possible targets for interventions designed to reduce SES disparities. The methods of cognitive neuroscience, such as neuropsy- chological testing and structural brain imaging, can help to identify specific neurocognitive systems that vary along socioeconomic gradients. The goal of the present study is to investigate the relation between SES and prefrontal cortical thickness in healthy normal children. We focus on prefrontal cortex for three reasons. First, this brain region is essential for executive function, which is associated with academic success (Blair & Diamond, 2008; Ursache, Blair & Raver, 2011) and intelligence as measured by psychometric tests (Deary, Penke & Johnson, 2010). Second, the long developmental trajectory of prefrontal cortex (Casey, Giedd & Thomas, 2000; Gogtay, Giedd, Lusk, Hayashi, Greenstein, Vaituzis, Nugent, Herman, Clasen, Toga, Rapoport & Thompson, 2004), and its sensitivity to environmental factors including stress (McEwen & Gianaros, 2011), suggest that differences in the experi- ences of lower and higher SES children could impact prefrontal development. Third, and most directly rele- vant, many studies have found SES differences in executive function and in prefrontal activity. In children ranging from infancy to adolescence, SES has been found to correlate with executive function as measured by many different tasks (Ardila, Rosselli, Matute & Guajardo, 2005; Lipina, Martelli, Vuelta & Colombo, 2005; Lipina, Martelli, Vuelta, Injoque-Ricle & Colombo, 2004; Mezzacappa, 2004; Sarsour, Sheri- dan, Jutte, Nuru-Jeter, Hinshaw & Boyce, 2011) and as measured by latent executive function constructs derived from multiple executive function tasks (Blair, Granger, Address for correspondence: Gwendolyn M. Lawson or Martha J. Farah, 3720 Walnut Street, Philadelphia, PA 19104, USA; e-mail: G.M. Lawson glawson@psych.upenn.edu or M.J. Farah mfarah@psych.upenn.edu 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 © 2013 John Wiley & Sons Ltd Developmental Science (2013), pp 1–12 DOI: 10.1111/desc.12096 D E S C 1 2 0 9 6 B Dispatch: 22.6.13 Journal: DESC CE: Wiley Journal Name Manuscript No. Author Received: No. of pages: 12 PE: Mageswari