Abstract

Working memory (WM) is assumed to consist of a process that sustains memory representations in an active state (maintenance) and a process that operates on these activated representations (manipulation). We examined evidence for two distinct, concurrent cognitive functions supporting maintenance and manipulation abilities by testing brain activity as participants performed a WM alphabetization task. Maintenance was investigated by varying the number of letters held in WM and manipulation by varying the number of moves required to sort the list alphabetically. We found that both maintenance and manipulation demand had significant effects on behavior that were associated with different cortical regions: maintenance was associated with bilateral prefrontal and left parietal cortex, and manipulation with right parietal activity, a link that is consistent with the role of parietal cortex in symbolic computations. Both structural and functional architecture of these systems suggested that these cognitive functions are supported by two dissociable brain networks. Critically, maintenance and manipulation functional networks became increasingly segregated with increasing demand, an effect that was positively associated with individual WM ability. These results provide evidence that network segregation may act as a protective mechanism to enable successful performance under increasing WM demand.

Details

Title
Complementary topology of maintenance and manipulation brain networks in working memory
Author
Davis, S W 1 ; Crowell, C A 2 ; Beynel, L 3 ; Deng, L 4 ; Lakhlani, D 5 ; Hilbig, S A 3 ; Lim, W 3 ; Nguyen, D 3 ; Peterchev, A V 6   VIAFID ORCID Logo  ; Luber, B M 7 ; Lisanby, S H 7 ; Appelbaum, L G 3 ; Cabeza, R 8 

1  Department of Neurology, Duke University School of Medicine, Durham, NC, USA; Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC, USA; Center for Cognitive Neuroscience, Duke University, Durham, NC, USA 
2  Department of Neurology, Duke University School of Medicine, Durham, NC, USA; Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC, USA 
3  Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC, USA 
4  Center for Cognitive Neuroscience, Duke University, Durham, NC, USA 
5  Department of Neurology, Duke University School of Medicine, Durham, NC, USA 
6  Department of Psychiatry and Behavioral Science, Duke University School of Medicine, Durham, NC, USA; Department of Biomedical Engineering, Duke University, Durham, NC, USA; Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA; Department of Neurosurgery, Duke University School of Medicine, Durham, NC, USA 
7  National Institute of Mental Health, Bethesda, MD, USA 
8  Center for Cognitive Neuroscience, Duke University, Durham, NC, USA; Department of Psychology & Neuroscience, Duke University, Durham, NC, USA 
Pages
1-14
Publication year
2018
Publication date
Dec 2018
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41598-018-35887-2
ProQuest document ID
2155894974
Copyright
© 2018. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.