title: Amygdala task-evoked activity and task-free connectivity independently contribute to feelings of arousal.
abstract: Individual differences in the intensity of feelings of arousal while viewing emotional pictures have been associated with the magnitude of task-evoked blood-oxygen dependent (BOLD) response in the amygdala. Recently, we reported that individual differences in feelings of arousal are associated with task-free (resting state) connectivity within the salience network. There has not yet been an investigation of whether these two types of functional magnetic resonance imaging (MRI) measures are redundant or independent in their relationships to behavior. Here we tested the hypothesis that a combination of task-evoked amygdala activation and task-free amygdala connectivity within the salience network relate to individual differences in feelings of arousal while viewing of negatively potent images. In 25 young adults, results revealed that greater task-evoked amygdala activation and stronger task-free amygdala connectivity within the salience network each contributed independently to feelings of arousal, predicting a total of 45% of its variance. Individuals who had both increased task-evoked amygdala activation and stronger task-free amygdala connectivity within the salience network had the most heightened levels of arousal. Task-evoked amygdala activation and task-free amygdala connectivity within the salience network were not related to each other, suggesting that resting-state and task-evoked dynamic brain imaging measures may provide independent and complementary information about affective experience, and likely other kinds of behaviors as well.
authors.affiliation: Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Massachusetts; Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Massachusetts; Psychiatric Neuroimaging Division, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Massachusetts.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Touroutoglou
authors.forename: Kevin C
authors.initials: KC
authors.lastname: Bickart
authors.forename: Lisa Feldman
authors.initials: LF
authors.lastname: Barrett
authors.forename: Bradford C
authors.initials: BC
authors.lastname: Dickerson
mesh_terms: D000328:Adult; D000679:Amygdala / Q000098:blood supply / Q000502:physiology*; D001143:Arousal / Q000502:physiology*; D001931:Brain Mapping; D017352:Echo-Planar Imaging; D004644:Emotions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology; D010100:Oxygen / Q000097:blood; D012309:Risk-Taking; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: amygdala; feelings of arousal; individual differences; resting-state connectivity; task-evoked activation