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Houck JM, Çetin MS, Mayer AR, Bustillo JR, Stephen J, Aine C, Cañive J, Perrone-Bizzozero N, Thoma RJ, Brookes MJ, Calhoun VD. Magnetoencephalographic and functional MRI connectomics in schizophrenia via intra- and inter-network connectivity. Neuroimage 2016; 145:96-106. [PMID: 27725313 DOI: 10.1016/j.neuroimage.2016.10.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 10/05/2016] [Accepted: 10/07/2016] [Indexed: 12/11/2022] Open
Abstract
Examination of intrinsic functional connectivity using functional MRI (fMRI) has provided important findings regarding dysconnectivity in schizophrenia. Extending these results using a complementary neuroimaging modality, magnetoencephalography (MEG), we present the first direct comparison of functional connectivity between schizophrenia patients and controls, using these two modalities combined. We developed a novel MEG approach for estimation of networks using MEG that incorporates spatial independent component analysis (ICA) and pairwise correlations between independent component timecourses, to estimate intra- and intern-network connectivity. This analysis enables group-level inference and testing of between-group differences. Resting state MEG and fMRI data were acquired from a large sample of healthy controls (n=45) and schizophrenia patients (n=46). Group spatial ICA was performed on fMRI and MEG data to extract intrinsic fMRI and MEG networks and to compensate for signal leakage in MEG. Similar, but not identical spatial independent components were detected for MEG and fMRI. Analysis of functional network connectivity (FNC; i.e., pairwise correlations in network (ICA component) timecourses) revealed a differential between-modalities pattern, with greater connectivity among occipital networks in fMRI and among frontal networks in MEG. Most importantly, significant differences between controls and patients were observed in both modalities. MEG FNC results in particular indicated dysfunctional hyperconnectivity within frontal and temporal networks in patients, while in fMRI FNC was always greater for controls than for patients. This is the first study to apply group spatial ICA as an approach to leakage correction, and as such our results may be biased by spatial leakage effects. Results suggest that combining these two neuroimaging modalities reveals additional disease-relevant patterns of connectivity that were not detectable with fMRI or MEG alone.
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Affiliation(s)
- Jon M Houck
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Mind Research Network, Albuquerque, New Mexico, United States.
| | - Mustafa S Çetin
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Mind Research Network, Albuquerque, New Mexico, United States; Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico, United States
| | - Andrew R Mayer
- Mind Research Network, Albuquerque, New Mexico, United States
| | - Juan R Bustillo
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Department of Psychiatry, University of New Mexico, Albuquerque, New Mexico, United States
| | - Julia Stephen
- Mind Research Network, Albuquerque, New Mexico, United States
| | - Cheryl Aine
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Mind Research Network, Albuquerque, New Mexico, United States; Department of Radiology, University of New Mexico, Albuquerque, New Mexico, United States
| | - Jose Cañive
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Department of Psychiatry, University of New Mexico, Albuquerque, New Mexico, United States
| | - Nora Perrone-Bizzozero
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Department of Neurosciences, University of New Mexico, Albuquerque, New Mexico, United States
| | - Robert J Thoma
- Center on Alcoholism, Substance Abuse, and Addictions, University of New Mexico, Albuquerque, New Mexico, United States; Department of Psychiatry, University of New Mexico, Albuquerque, New Mexico, United States
| | - Matthew J Brookes
- Department of Psychiatry, University of New Mexico, Albuquerque, New Mexico, United States; University of Nottingham, United Kingdom
| | - Vince D Calhoun
- Mind Research Network, Albuquerque, New Mexico, United States; Department of Electrical and Computer Engineering, University of New Mexico, Albuquerque, New Mexico, United States
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Mayer AR, Ruhl D, Merideth F, Ling J, Hanlon FM, Bustillo J, Cañive J. Functional imaging of the hemodynamic sensory gating response in schizophrenia. Hum Brain Mapp 2012; 34:2302-12. [PMID: 22461278 DOI: 10.1002/hbm.22065] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 01/06/2012] [Accepted: 02/02/2012] [Indexed: 11/11/2022] Open
Abstract
The cortical (auditory and prefrontal) and/or subcortical (thalamic and hippocampal) generators of abnormal electrophysiological responses during sensory gating remain actively debated in the schizophrenia literature. Functional magnetic resonance imaging has the spatial resolution for disambiguating deep or simultaneous sources but has been relatively under-utilized to investigate generators of the gating response. Thirty patients with chronic schizophrenia (SP) and 30 matched controls participated in the current experiment. Hemodynamic response functions (HRFs) for single (S1) and pairs (S1 + S2) of identical ("gating-out" redundant information) or nonidentical ("gating-in" novel information) tones were generated through deconvolution. Increased or prolonged activation for patients in conjunction with deactivation for controls was observed within auditory cortex, prefrontal cortex, and thalamus in response to single tones during the late hemodynamic response, and these group differences were not associated with clinical or cognitive symptomatology. Although patient hyperactivation to paired-tones conditions was present in several regions of interest, the effects were not statistically significant for either the gating-out or gating-in conditions. Finally, abnormalities in the postundershoot of the auditory HRF were also observed for both single and paired-tones conditions in patients. In conclusion, the amalgamation of the entire electrophysiological response to both S1 and S2 stimuli may limit hemodynamic sensitivity to paired tones during sensory gating, which may be more readily overcome by paradigms that use multiple stimuli rather than pairs. Patient hyperactivation following single tones is suggestive of deficits in basic inhibition, neurovascular abnormalities, or a combination of both factors.
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Affiliation(s)
- Andrew R Mayer
- Mind Research Network and Lovelace Biomedical and Environmental Research Institute, 1101 Yale Blvd. NE, Albuquerque, New Mexico 87106, USA.
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