The pulse: transient fMRI signal increases in subcortical arousal systems during transitions in attention
Rong Li,
Jun Hwan Ryu,
Peter Vincent,
Max Springer,
Dan Kluger,
Erik A. Levinsohn,
Yu Chen,
Huafu Chen,
Hal Blumenfeld
Affiliations
Rong Li
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, P R China
Jun Hwan Ryu
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Peter Vincent
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Max Springer
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Dan Kluger
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Erik A. Levinsohn
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Yu Chen
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States
Huafu Chen
MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 610054, P R China
Hal Blumenfeld
Departments of Neurology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; Departments of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; Departments of Neurosurgery, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, United States; Corresponding author.
Studies of attention emphasize cortical circuits for salience monitoring and top-down control. However, subcortical arousal systems have a major influence on dynamic cortical state. We hypothesize that task-related increases in attention begin with a “pulse” in subcortical arousal and cortical attention networks, which are reflected indirectly through transient fMRI signals. We conducted general linear model and model-free analyses of fMRI data from two cohorts and tasks with mixed block and event-related design. 46 adolescent subjects at our center and 362 normal adults from the Human Connectome Project participated. We identified a core shared network of transient fMRI increases in subcortical arousal and cortical salience/attention networks across cohorts and tasks. Specifically, we observed a transient pulse of fMRI increases both at task block onset and with individual task events in subcortical arousal areas including midbrain tegmentum, thalamus, nucleus basalis and striatum; cortical-subcortical salience network regions including the anterior insula/claustrum and anterior cingulate cortex/supplementary motor area; in dorsal attention network regions including dorsolateral frontal cortex and inferior parietal lobule; as well as in motor regions including cerebellum, and left hemisphere hand primary motor cortex. The transient pulse of fMRI increases in subcortical and cortical arousal and attention networks was consistent across tasks and study populations, whereas sustained activity in these same networks was more variable. The function of the transient pulse in these networks is unknown. However, given its anatomical distribution, it could participate in a neuromodulatory surge of activity in multiple parallel neurotransmitter systems facilitating dynamic changes in conscious attention.
