title: Sliding-window analysis tracks fluctuations in amygdala functional connectivity associated with physiological arousal and vigilance during fear conditioning.
abstract: We evaluated whether sliding-window analysis can reveal functionally relevant brain network dynamics during a well-established fear conditioning paradigm. To this end, we tested if fMRI fluctuations in amygdala functional connectivity (FC) can be related to task-induced changes in physiological arousal and vigilance, as reflected in the skin conductance level (SCL). Thirty-two healthy individuals participated in the study. For the sliding-window analysis we used windows that were shifted by one volume at a time. Amygdala FC was calculated for each of these windows. Simultaneously acquired SCL time series were averaged over time frames that corresponded to the sliding-window FC analysis, which were subsequently regressed against the whole-brain seed-based amygdala sliding-window FC using the GLM. Surrogate time series were generated to test whether connectivity dynamics could have occurred by chance. In addition, results were contrasted against static amygdala FC and sliding-window FC of the primary visual cortex, which was chosen as a control seed, while a physio-physiological interaction (PPI) was performed as cross-validation. During periods of increased SCL, the left amygdala became more strongly coupled with the bilateral insula and anterior cingulate cortex, core areas of the salience network. The sliding-window analysis yielded a connectivity pattern that was unlikely to have occurred by chance, was spatially distinct from static amygdala FC and from sliding-window FC of the primary visual cortex, but was highly comparable to that of the PPI analysis. We conclude that sliding-window analysis can reveal functionally relevant fluctuations in connectivity in the context of an externally cued task.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany; Max Planck Institute for Human Cognitive and Brain Sciences, Max Planck Research Group for Neuroanatomy & Connectivity, Leipzig, Germany; Department of Psychology, Leipzig University, Leipzig, Germany; International Max Planck Research School NeuroCom, Leipzig, Germany. Electronic address: baczkowski@cbs.mpg.de.
authors.forename: Blazej M
authors.initials: BM
authors.lastname: Baczkowski
authors.affiliation: Centre for Integrative Neuroscience and Neurodynamics, Department of Psychology, University of Reading, Reading, United Kingdom.
authors.forename: Tom
authors.initials: T
authors.lastname: Johnstone
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
authors.forename: Henrik
authors.initials: H
authors.lastname: Walter
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Erk
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité - Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany. Electronic address: ilya.veer@charite.de.
authors.forename: Ilya M
authors.initials: IM
authors.lastname: Veer
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001143:Arousal; D001921:Brain / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D003214:Conditioning, Classical; D005239:Fear / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D055815:Young Adult
keywords: Amygdala; Dynamic connectivity; Fear conditioning; Functional connectivity; Sliding-window analysis