Trauma moderates the development of the oscillatory dynamics serving working memory in a sex-specific manner.

Working memory, the ability to hold items in memory stores for further manipulation, is a higher order cognitive process that supports many aspects of daily life. Childhood trauma has been associated with altered cognitive development including particular deficits in verbal working memory (VWM), but the neural underpinnings remain poorly understood. Magnetoencephalography (MEG) studies of VWM have reliably shown decreased alpha activity in left-lateralized language regions during encoding, and increased alpha activity in parieto-occipital cortices during the maintenance phase. In this study, we examined whether childhood trauma affects behavioral performance and the oscillatory dynamics serving VWM using MEG in a cohort of 9- to 15-year-old youth. All participants completed a modified version of the UCLA Trauma History Profile and then performed a VWM task during MEG. Our findings indicated a sex-by-age-by-trauma three-way interaction, whereby younger females experiencing higher levels of trauma had the lowest d' accuracy scores and the strongest positive correlations with age (i.e. older performed better). Likewise, females with higher levels of childhood trauma exhibited altered age-related alpha changes during the maintenance phase within the right temporal and parietal cortices. These findings suggest that trauma exposure may alter the developmental trajectory of neural oscillations serving VWM processing in a sex-specific way.