Intrinsic brain indices of verbal working memory capacity in children and adolescents

Abstract

Working memory (WM) is central to the acquisition of knowledge and skills throughout childhood and adolescence. While numerous behavioral and task-based fMRI studies have examined WM development, few have used resting-state fMRI (R-fMRI). Here, we present a systematic R-fMRI examination of age-related differences in the neural indices of verbal WM performance in a cross-sectional pediatric sample (ages: 7–17; n=68), using data-driven approaches. Verbal WM capacity was measured with the digit span task, a commonly used educational and clinical assessment. We found distinct neural indices of digit span forward (DSF) and backward (DSB) performance, reflecting their unique neuropsychological demands. Regardless of age, DSB performance was related to intrinsic properties of brain areas previously implicated in attention and cognitive control, while DSF performance was related to areas less commonly implicated in verbal WM storage (precuneus, lateral visual areas). From a developmental perspective, DSF exhibited more robust age-related differences in brain-behavior relationships than DSB, and implicated a broader range of networks (ventral attention, default, somatomotor, limbic networks) - including a number of regions not commonly associated with verbal WM (angular gyrus, subcallosum). These results highlight the importance of examining the neurodevelopment of verbal WM and of considering regions beyond the “usual suspects”.

The developmental relationship between specific cognitive domains and grey matter in the cerebellum

“…For reading, this interaction pattern is consistent with a recent meta-analysis of fMRI findings, in which there was significant converging cerebellar activation in studies of adults but not children (Martin, Schurz, Kronbichler, & Richlan, 2015). Moreover, in a recent study of children aged 7–17 years, Yang et al (2015) found a negative relationship between a measure of working memory and resting-state functional connectivity in bilateral lobules VI and VIII in younger children, but a positive relationship in older children. Although we found no significant relationship between cerebellar GM and processing speed scores in the full sample, we found significant age × processing speed interactions in several regions, including bilateral lobule VIII.…”

Aberrant Temporal Connectivity in Persons at Clinical High Risk for Psychosis

“…Whole-brain analyses using MDMR have been used in different cohorts including pediatric samples (72), individuals with Attention Deficit/Hyperactivity Disorder (40, 73), cohorts with psychosis-spectrum symptoms (35) as well as depression and post-traumatic stress disorder (74). Compared to classic seed-based analyses, MDMR has the advantage of using information from all voxels in order to identify “hot spots” of dysconnectivity.…”

Computerized cognitive training for children with neurofibromatosis type 1: A pilot resting-state fMRI study

“…We sought to identify reliable regionally specifiable changes in spontaneous BOLD fluctuations by contrasting pre- with post-treatment resting state scans. Accordingly, we performed univariate voxel-wise analyses on a set of four indices of spontaneous resting state activity that have been used previously to examine neural correlates of working memory in typically developing children and adolescents (Yang et al, 2015), including two regional measures – fractional amplitude of low frequency fluctuations (fALFF, Zou et al, 2008) and regional homogeneity (ReHo, Zang et al, 2004). Additionally, to probe behavioral improvement, standardized Cogstate tasks (Maruff et al, 2009) were administered before and after Cogmed training completion.…”