Association between Hippocampal Volume and Working Memory in 10,000+ 9–10-Year-Old Children: Sex Differences

Abstract

Aim: This study tested sex differences in the association between hippocampal volume and working memory of a national sample of 9–10-year-old children in the US. As the hippocampus is functionally lateralized (especially in task-related activities), we explored the results for the right and the left hippocampus. Methods: This is a cross-sectional study using the Adolescent Brain Cognitive Development (ABCD) Study data. This analysis included baseline ABCD data (n = 10,093) of children between ages 9 and 10 years. The predictor variable was right and left hippocampal volume measured by structural magnetic resonance imaging (sMRI). The primary outcome, list sorting working memory, was measured using the NIH toolbox measure. Sex was the moderator. Age, race, ethnicity, household income, parental education, and family structure were the covariates. Results: In the overall sample, larger right (b = 0.0013; p < 0.001) and left (b = 0.0013; p < 0.001) hippocampal volumes were associated with higher children’s working memory. Sex had statistically significant interactions with the right (b = −0.0018; p = 0.001) and left (b = −0.0012; p = 0.022) hippocampal volumes on children’s working memory. These interactions indicated stronger positive associations between right and left hippocampal volume and working memory for females compared to males. Conclusion: While right and left hippocampal volumes are determinants of children’s list sorting working memory, these effects seem to be more salient for female than male children. Research is needed on the role of socialization, sex hormones, and brain functional connectivity as potential mechanisms that may explain the observed sex differences in the role of hippocampal volume as a correlate of working memory.

Peer victimization (bullying) on mental health, behavioral problems, cognition, and academic performance in preadolescent children in the ABCD Study

“…We identified that boys performed better than girls on the working memory task, which is inconsistent with the previous findings that women outperform men on visual working memory tests ( Harness et al, 2008 ) and no sex differences were found in verbal working memory ( Harness et al, 2008 ; Tulsky et al, 2014 ). However, our result was consistent with that in a prior ABCD paper ( Assari et al, 2021 ). These disparate findings demonstrate that sex differences in working memory performance differ in preadolescent children compared to adults ( Harness et al, 2008 ; Tulsky et al, 2014 ).…”

The sexual brain, genes, and cognition: A machine‐predicted brain sex score explains individual differences in cognitive intelligence and genetic influence in young children

“…Sex impacts the development of the brain, cognition, and behaviors. Sex differences in psychological cognitive well‐being, mental, and cognitive health outcomes (Assari, Boyce, & Jovanovic, 2021 ) and psychopathology (Loso et al, 2021 ) may originate from sex differences in brain structure and function in children. Several studies attempted to test the sex‐dependent structural and functional variations in the brains of males and females in youth (Satterthwaite et al, 2015 ; Sepehrband et al, 2018 ).…”

Sex differences in dorsolateral prefrontal cortical and superior colliculus activities support the impact of alcohol use severity and sleep deficiency on two-back memory

“…A review with meta-analysis discussed sex differences in sleep loss-induced cognitive deficits, with the majority of studies reporting greater impacts of sleep loss on cognitive health in women than in men ( 45 ). A more recent study tested sex differences in the association between hippocampal volume and working memory in a national sample of children 9 to 10 years old and reported larger bilateral hippocampal volumes in association with better working memory ( 46 ). Further, females vs. males showed stronger positive associations between the hippocampal volumes and working memory.…”