title: Modulating intrinsic connectivity: adjacent subregions within supplementary motor cortex, dorsolateral prefrontal cortex, and parietal cortex connect to separate functional networks during task and also connect during rest.
abstract: Supplementary motor area (SMA), the inferior frontal junction (IFJ), superior frontal junction (SFJ) and parietal cortex are active in many cognitive tasks. In a previous study, we found that subregions of each of these major areas were differentially active in component processes of executive function during working memory tasks. In the present study, each of these subregions was used as a seed in a whole brain functional connectivity analysis of working memory and resting state data. These regions show functional connectivity to different networks, thus supporting the parcellation of these major regions into functional subregions. Many regions showing significant connectivity during the working memory residual data (with task events regressed from the data) were also significantly connected during rest suggesting that these network connections to subregions within major regions of cortex are intrinsic. For some of these connections, task demands modulate activity in these intrinsic networks. Approximately half of the connections significant during task were significant during rest, indicating that some of the connections are intrinsic while others are recruited only in the service of the task. Furthermore, the network connections to traditional 'task positive' and 'task negative' (a.k.a 'default mode') regions shift from positive connectivity to negative connectivity depending on task demands. These findings demonstrate that such task-identified subregions are part of distinct networks, and that these networks have different patterns of connectivity for task as they do during rest, engaging connections both to task positive and task negative regions. These results have implications for understanding the parcellation of commonly active regions into more specific functional networks.
authors.affiliation: Department of Social Sciences, Concordia College New York, Bronxville, New York, United States of America.
authors.forename: Jennifer K
authors.initials: JK
authors.lastname: Roth
authors.affiliation: Department of Psychology, Yale University School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: Marcia K
authors.initials: MK
authors.lastname: Johnson
authors.affiliation: Magnetic Resonance Research Center, Department of Diagnostic Radiology, Yale School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: Fuyuze
authors.initials: F
authors.lastname: Tokoglu
authors.affiliation: Child Study Center, Yale University School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: Isabella
authors.initials: I
authors.lastname: Murphy
authors.affiliation: Departments of Biomedical Engineering, and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut, United States of America.
authors.forename: R Todd
authors.initials: RT
authors.lastname: Constable
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002540:Cerebral Cortex / Q000502:physiology*; D016000:Cluster Analysis; D063132:Connectome; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology; D012146:Rest; D055815:Young Adult