Distinct functional and structural neural underpinnings of working memory

• Published in: NeuroImage (Orlando, Fla.) Vol. 174; pp. 463 - 471
• Main Authors: Owens, Max M., Duda, Bryant, Sweet, Lawrence H., MacKillop, James
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2018; Elsevier Limited
• Subjects: Accuracy; Adult; Apoptosis Regulatory Proteins; Brain - anatomy & histology; Brain - physiology; Cognition; Connectome; Female; Frontal gyrus; Functional anatomy; Functional MRI; Hispanic Americans; Homology; Humans; Male; Memory; Memory, Short-Term - physiology; N-Back; Neuropsychological Tests; NMR; Nuclear magnetic resonance; Short term memory; Structural MRI; Structure-function relationships; Studies; Substantia grisea; Superior parietal lobule; Visual cortex; Working memory; Young Adult; Structural MRI; Functional MRI; Working memory; N-Back
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2018.03.022

Working memory (WM), the short-term abstraction and manipulation of information, is an essential neurocognitive process in daily functioning. Few studies have concurrently examined the functional and structural neural correlates of WM and the current study did so to characterize both overlapping and unique associations. Participants were a large sample of adults from the Human Connectome Project (N = 1064; 54% female) who completed an in-scanner visual N-back WM task. The results indicate a clear dissociation between BOLD activation during the WM task and brain structure in relation to performance. In particular, while activation in the middle frontal gyrus was positively associated with WM performance, cortical thickness in this region was inversely associated with performance. Additional unique associations with WM were BOLD activation in superior parietal lobule, cingulate, and fusiform gyrus and gray matter volume in the orbitofrontal cortex and cuneus. Across findings, substantially larger effects were observed for functional associations relative to structural associations. These results provide further evidence implicating frontoparietal subunits of the brain in WM. Moreover, these findings reveal the distinct, and in some cases opposing, roles of brain structure and neural activation in WM, highlighting the lack of homology between structure and function in relation to cognition.
•Investigation of the functional and structural neural correlates of working memory.•Measured by a visual N-Back task in a large adult sample (N = 1064).•Larger associations for BOLD signal relative to morphometry.•Lack of homology between structure and function in relation to cognition.•Dissociation especially notable for middle frontal gyrus.