title: Default mode network deactivation during odor-visual association.
abstract: Default mode network (DMN) deactivation has been shown to be functionally relevant for goal-directed cognition. In this study, the DMN's role during olfactory processing was investigated using two complementary functional magnetic resonance imaging (fMRI) paradigms with identical timing, visual-cue stimulation, and response monitoring protocols. Twenty-nine healthy, non-smoking, right-handed adults (mean age = 26 ± 4 years, 16 females) completed an odor-visual association fMRI paradigm that had two alternating odor + visual and visual-only trial conditions. During odor + visual trials, a visual cue was presented simultaneously with an odor, while during visual-only trial conditions the same visual cue was presented alone. Eighteen of the twenty-nine participants (mean age = 27.0 ± 6.0 years, 11 females) also took part in a control no-odor fMRI paradigm that consisted of a visual-only trial condition which was identical to the visual-only trials in the odor-visual association paradigm. Independent Component Analysis (ICA), extended unified structural equation modeling (euSEM), and psychophysiological interaction (PPI) were used to investigate the interplay between the DMN and olfactory network. In the odor-visual association paradigm, DMN deactivation was evoked by both the odor + visual and visual-only trial conditions. In contrast, the visual-only trials in the no-odor paradigm did not evoke consistent DMN deactivation. In the odor-visual association paradigm, the euSEM and PPI analyses identified a directed connectivity between the DMN and olfactory network which was significantly different between odor + visual and visual-only trial conditions. The results support a strong interaction between the DMN and olfactory network and highlights the DMN's role in task-evoked brain activity and behavioral responses during olfactory processing. Hum Brain Mapp 38:1125-1139, 2017. © 2016 Wiley Periodicals, Inc.
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Prasanna R
authors: PR
authors: Karunanayaka
authors: Emotional Brain Institute, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York.|Department of Child & Adolescent Psychiatry, New York University School of Medicine, New York, New York.
authors: Donald A
authors: DA
authors: Wilson
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Michael J
authors: MJ
authors: Tobia
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Brittany E
authors: BE
authors: Martinez
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.|Department of Neurosurgery, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Mark D
authors: MD
authors: Meadowcroft
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.|Department of Neurology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Paul J
authors: PJ
authors: Eslinger
authors: Department of Radiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.|Department of Neurosurgery, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania.
authors: Qing X
authors: QX
authors: Yang
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000502:physiology*; D001931:Brain Mapping; D003463:Cues; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000502:physiology*; D009483:Neuropsychological Tests; D009812:Odorants; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D012903:Smell / Q000502:physiology*; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: default mode network (DMN); fMRI; olfaction