The effect of early life stress on brain white matter integrity and working memory performance

Abstract

Former studies revealed that exposure to early life adversity is correlated with alterations in the white matter structure, particularly, in the areas associated with executive functioning and memory. Those alterations include both volume and microstructural white matter integrity reductions in the brain. A vast amount of the studies focused on volume reductions, and it is not clear whether the alterations in the white matter integrity is associated with cognitive functioning. The current study investigated the influence of early life stress on white matter integrity in the anterior cingulate cortex (ACC)and corpus callosum (CC) among the forty-six healthy participants. Participants were split into two groups based on the Childhood Experience of Care and Abuse Questionnaire (CECA.Q). Participants with relatively low early life stress were compared with participants with relatively high early life stress on fractional anisotropy (FA) and mean diffusivity (MD) values in the ACC and CC. Another analysis investigated the working memory performance of the participants in the n-back task. Findings revealed that low-level early life stress did not significantly differ from high-level of early life stress in terms of FA values. However, there were significantly higher MD values in the high-level early life stress group compared to low-level early life stress group. In terms of cognitive performance, there were no performance differences between the two groups on the n-back task. The findings suggest that the high level of early life stress is associated with subtle white matter integrity changes in the brain but does not affect the performance.