The neural correlates of reasoning differ by socioeconomic status in development

• In Event: 3-169 - Socioeconomic Status, Brain, and Cognitive Development: Environmental Mechanisms and Individual Differences

Integrative Statement

Although lower socioeconomic status (SES) is generally negatively associated with performance on cognitive assessments, some children from lower-SES backgrounds perform as well as their peers from higher-SES backgrounds. Yet little research has examined whether the neural correlates of individual differences in cognition vary by SES. The current study explored whether relationships between cortical structure and fluid reasoning differ by SES in early childhood.

Here, we focused on fluid reasoning, a component of performance IQ that is highly correlated with academic performance and differs by SES. Fluid reasoning has been well-characterized from a neural perspective: it relies on a distributed frontoparietal network, with evidence for a specific role of rostrolateral prefrontal cortex (RLPFC).

In a sample of 115 4-7 year olds, fluid reasoning positively correlated wtih SES, indexed by higest level of completed maternal education (r(112) = .31, p = .001). In whole brain cortical thickness analyses, there was a significant interaction between SES and matrix reasoning on cortical thickness in RLPFC (cluster-forming p < .005, cluster-wise p < .05, adjusted for both hemispheres; Figure 1A). Specifically, thicker bilateral RLPFC positively correlated with reasoning ability in children from lower-SES backgrounds, but not in children from higher-SES backgrounds. Given the exploratory nature of our analyses, we aimed to replicate our results in an independent sample of 59 adolescents. We focused our analyses on a priori regions of interest identified in the early childhood sample: left and right RMFG. Our results replicated in the adolescent sample, with thicker bilateral RLPFC positively relating to reasoning only in children from lower-SES backgrounds (Figure 1B).

Furthermore, young children from lower-SES backgrounds with strong reasoning skills showed a unique developmental time course of RLPFC: they were the only group to show a positive relationship between RLPFC thickness and age (Figure 2). However, the positive relationship between RLPFC thickness and age in high-performing children from lower-SES backgrounds was not significant in the adolescent sample, indicating that this relationship may be specific to early childhood development.

In sum, we found that relationships between cortical thickness and cognition differ by SES during development. Future work should continue to explore how positive brain development occurs differentially across varied SES experiences so as to promote brain development in a way that is valid for each child according to his or her environment.

Authors

• Julia A. Leonard, Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute to Technology;
  Presenting Author

• Rachel R. Romeo, 1Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research; Division of Medical Sciences, Harvard University
  Non-Presenting Author

• Anne T. Park, University of Pennsylvania
  Non-Presenting Author

• Megumi E. Takada, Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research
  Non-Presenting Author

• Sydney T. Robinson, Department of Psychology, University of Pennsylvania
  Non-Presenting Author

• Hannah Grotzinger, Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research
  Non-Presenting Author

• Briana S Last, Department of Psychology, University of Pennsylvania
  Non-Presenting Author

• Amy S Finn, University of Toronto
  Non-Presenting Author

• John D.E. Gabrieli, Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research
  Non-Presenting Author

• Allyson Mackey, University of Pennsylvania
  Non-Presenting Author