251
|
Somandepalli K, Kelly C, Reiss PT, Zuo XN, Craddock RC, Yan CG, Petkova E, Castellanos FX, Milham MP, Di Martino A. Short-term test-retest reliability of resting state fMRI metrics in children with and without attention-deficit/hyperactivity disorder. Dev Cogn Neurosci 2015; 15:83-93. [PMID: 26365788 PMCID: PMC6989828 DOI: 10.1016/j.dcn.2015.08.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 08/07/2015] [Accepted: 08/09/2015] [Indexed: 01/05/2023] Open
Abstract
Children with or without ADHD have moderate/high R-fMRI test–retest reliability. Reliability is greater in controls than ADHD across most R-fMRI metrics. Regional differences in ICC related to diagnostic groups reflect underlying pathophysiology for ADHD affecting both inter and intra subject variability.
To date, only one study has examined test–retest reliability of resting state fMRI (R-fMRI) in children, none in clinical developing groups. Here, we assessed short-term test–retest reliability in a sample of 46 children (11–17.9 years) with attention-deficit/hyperactivity disorder (ADHD) and 57 typically developing children (TDC). Our primary test–retest reliability measure was the intraclass correlation coefficient (ICC), quantified for a range of R-fMRI metrics. We aimed to (1) survey reliability within and across diagnostic groups, and (2) compare voxel-wise ICC between groups. We found moderate-to-high ICC across all children and within groups, with higher-order functional networks showing greater ICC. Nearly all R-fMRI metrics exhibited significantly higher ICC in TDC than in children with ADHD for one or more regions. In particular, posterior cingulate and ventral precuneus exhibited group differences in ICC across multiple measures. In the context of overall moderate-to-high test–retest reliability in children, regional differences in ICC related to diagnostic groups likely reflect the underlying pathophysiology for ADHD. Our currently limited understanding of the factors contributing to inter- and intra-subject variability in ADHD underscores the need for large initiatives aimed at examining their impact on test–retest reliability in both clinical and developing populations.
Collapse
Affiliation(s)
- Krishna Somandepalli
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA
| | - Clare Kelly
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA
| | - Philip T Reiss
- Division of Biostatistics, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA; Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Xi-Nian Zuo
- Key Laboratory of Behavioral Science and Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - R C Craddock
- Center for the Developing Brain, Child Mind Institute, 445 Park Avenue, New York, NY 10022, USA; Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Chao-Gan Yan
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA; Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA; Key Laboratory of Behavioral Science and Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| | - Eva Petkova
- Division of Biostatistics, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA; Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - F X Castellanos
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA; Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Michael P Milham
- Center for the Developing Brain, Child Mind Institute, 445 Park Avenue, New York, NY 10022, USA; Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Adriana Di Martino
- Phyllis Green and Randolph Cowen Institute for Pediatric Neuroscience, The Child Study Center at NYU Langone Medical Center, 1 Park Avenue, New York, NY 10016, USA.
| |
Collapse
|
252
|
Liang M, Xie B, Yang H, Yu L, Yin X, Wei L, Wang J. Distinct patterns of spontaneous brain activity between children and adults with anisometropic amblyopia: a resting-state fMRI study. Graefes Arch Clin Exp Ophthalmol 2015; 254:569-76. [PMID: 26245338 DOI: 10.1007/s00417-015-3117-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 06/08/2015] [Accepted: 07/18/2015] [Indexed: 01/13/2023] Open
Abstract
PURPOSE To detect the altered spontaneous brain activity patterns in children and adults with anisometropic amblyopia using resting-state functional magnetic resonance imaging (rs-fMRI) technique combined with the amplitude of low-frequency fluctuation (ALFF) method. METHODS Thirty-two monocular anisometropic amblyopia and 34 normal-sight controls were divided into child group and adult group. Rs-fMRI was performed in all participants and analysis of ALFF value within the whole brain was conducted in each subject. ALFF value differences between the patients and controls in the two groups were compared via an independent two-sample t test. RESULTS The amblyopic children mainly exhibited increased ALFF in part of the bilateral calcarine (BA17), the left middle occipital gyrus (BA18/19), and the left postcentral gyrus (BA2). By contrast, the amblyopic adults showed decreased ALFF in the bilateral precuneus cortex (part of BA7), and the standardized ALFF value of bilateral precuneus were correlated with the amount of anisometropia of the amblyopic adults. CONCLUSIONS Rs-fMRI is an effective noninvasive technique for exploring brain activity of the anisometropic amblyopia. Our findings demonstrated that brain activity changed both in amblyopic children and adults under the resting state, and revealed the differences in spontaneous activity patterns between the amblyopic children and adults.
Collapse
Affiliation(s)
- Minglong Liang
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Bing Xie
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Hong Yang
- Ophthalmology Research Center, Southwest Eye Hospital/Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Longhua Yu
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China.,Department of Radiology, 401st Hospital of PLA, Qingdao, Shandong Province, China
| | - Xuntao Yin
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Luqing Wei
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing, 400038, China.
| |
Collapse
|
253
|
Tu PC, Lee YC, Chen YS, Hsu JW, Li CT, Su TP. Network-specific cortico-thalamic dysconnection in schizophrenia revealed by intrinsic functional connectivity analyses. Schizophr Res 2015; 166:137-43. [PMID: 26081977 DOI: 10.1016/j.schres.2015.05.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/15/2015] [Accepted: 05/01/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Cortico-thalamic connections are thought to be abnormal in schizophrenia due to their important roles in sensory relay and higher cognitive control, both of which are affected by this devastating illness. This study tested the cortico-thalamic dysconnection hypothesis in schizophrenia and further explored cortico-thalamic network properties using functional connectivity MRI (fcMRI). METHODS Forty-eight participants with schizophrenia and 48 healthy controls underwent resting fMRI scans and clinical evaluations. Six a priori cortical regions of interests (ROIs) were used to derive the six networks: dorsal default mode network (dDMN), fronto-parietal network (FPN), cingulo-opercular network (CON), primary sensorimotor network (SM1), primary auditory network (A1) and primary visual network (V1). The cortico-thalamic connectivity for each network was calculated for each participant and then compared between groups. RESULTS A repeated measures analysis of variance (ANOVA) showed significant group×network interactions (F(5, 90)=9.5, P<0.001), which were driven by a significant increase in FC within the SM1 (t(94)=4.1, P<0.001) and A1 (t(94)=4.2, P<0.001) networks in schizophrenics, as well as a significant decrease within the CON (t(94)=-2.8, P=0.04). The cortico-thalamic dysconnection did not correlate with symptom severity, representing a state independent abnormality. CONCLUSION The network analysis indicates that cortico-thalamic dysconnection in schizophrenia involves multiple networks and shows network specific changes. The findings provide support for dysfunctional thalamus-related networks in schizophrenia and further elaborate their network properties.
Collapse
Affiliation(s)
- Pei-Chi Tu
- Department of Medical Research and Education, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Institute of Philosophy of Mind and Cognition, National Yang-Ming University, Taipei, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ying-Chiao Lee
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ying-Shiue Chen
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ju-Wei Hsu
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Cheng-Ta Li
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Tung-Ping Su
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei 112, Taiwan; Department of Psychiatry, Faculty of Medicine, National Yang-Ming University, Taipei, Taiwan.
| |
Collapse
|
254
|
Abstract
The network approach is increasingly being applied to the investigation of normal brain function and its impairment. In the present review, we introduce the main methodological approaches employed for the analysis of resting‐state neuroimaging data in Parkinson's disease studies. We then summarize the results of recent studies that used a functional network perspective to evaluate the changes underlying different manifestations of Parkinson's disease, with an emphasis on its cognitive symptoms. Despite the variability reported by many studies, these methods show promise as tools for shedding light on the pathophysiological substrates of different aspects of Parkinson's disease, as well as for differential diagnosis, treatment monitoring and establishment of imaging biomarkers for more severe clinical outcomes.
Collapse
Affiliation(s)
- Hugo C Baggio
- Departament de Psiquiatria i Psicobiologia Clínica, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Bàrbara Segura
- Departament de Psiquiatria i Psicobiologia Clínica, Universitat de Barcelona, Barcelona, Catalonia, Spain
| | - Carme Junque
- Departament de Psiquiatria i Psicobiologia Clínica, Universitat de Barcelona, Barcelona, Catalonia, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Catalonia, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Barcelona, Catalonia, Spain
| |
Collapse
|
255
|
Loitfelder M, Pinter D, Langkammer C, Jehna M, Ropele S, Fazekas F, Schmidt R, Enzinger C. Functional connectivity analyses using emulated and conventional resting-state data: parts versus the whole story. Brain Connect 2015; 4:842-8. [PMID: 25389907 DOI: 10.1089/brain.2013.0220] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Continuous resting-state (RS) functional magnetic resonance imaging (fMRI) has become particularly useful to identify changes in functional connectivity (FC) in CNS disorders. Fair et al. proposed a method of volume extraction to emulate RS fMRI from block-design experiments. Whether the validity of this approach holds true in multiple sclerosis (MS) patients has not been tested formally so far. Twelve MS patients and 18 controls underwent conventional RS fMRI and a cognitive block-design fMRI. The total amount of volumes as well as the truncated set of volumes of both functional datasets was separately analyzed using a seed-based approach. Overall, seed-based analyses of FC from the anterior cingulated cortex allowed identification of the same key-network constituents using different analytical approaches, whereas higher-level within-group analyses of emulated RS versus continuous RS also revealed significant distinct differences in FC networks. Using the emulated RS approach, a general identification of connectivity networks similar to those obtained using conventional RS data also appears feasible in diseased brains. Higher-level contrasts, however, yielded different results attesting to a significant impact of employed methodology.
Collapse
Affiliation(s)
- Marisa Loitfelder
- 1 Department of Neurology, Medical University of Graz , Graz, Austria
| | | | | | | | | | | | | | | |
Collapse
|
256
|
Andellini M, Cannatà V, Gazzellini S, Bernardi B, Napolitano A. Test-retest reliability of graph metrics of resting state MRI functional brain networks: A review. J Neurosci Methods 2015; 253:183-92. [PMID: 26072249 DOI: 10.1016/j.jneumeth.2015.05.020] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 12/31/2022]
Abstract
The employment of graph theory to analyze spontaneous fluctuations in resting state BOLD fMRI data has become a dominant theme in brain imaging studies and neuroscience. Analysis of resting state functional brain networks based on graph theory has proven to be a powerful tool to quantitatively characterize functional architecture of the brain and it has provided a new platform to explore the overall structure of local and global functional connectivity in the brain. Due to its increased use and possible expansion to clinical use, it is essential that the reliability of such a technique is very strongly assessed. In this review, we explore the outcome of recent studies in network reliability which apply graph theory to analyze connectome resting state networks. Therefore, we investigate which preprocessing steps may affect reproducibility the most. In order to investigate network reliability, we compared the test-retest (TRT) reliability of functional data of published neuroimaging studies with different preprocessing steps. In particular we tested influence of global signal regression, correlation metric choice, binary versus weighted link definition, frequency band selection and length of time-series. Statistical analysis shows that only frequency band selection and length of time-series seem to affect TRT reliability. Our results highlight the importance of the choice of the preprocessing steps to achieve more reproducible measurements.
Collapse
Affiliation(s)
- Martina Andellini
- Medical Physics Department, Enterprise Risk Management, Bambino Gesù Children's Hospital, Rome, Lazio, Italy.
| | - Vittorio Cannatà
- Medical Physics Department, Enterprise Risk Management, Bambino Gesù Children's Hospital, Rome, Lazio, Italy
| | - Simone Gazzellini
- Department of Neuroscience and Neurorehabilitation, Bambino Gesù Children's Hospital, Rome, Lazio, Italy
| | - Bruno Bernardi
- Unit of Neuroradiology, Bambino Gesù Children's Hospital, Rome, Lazio, Italy
| | - Antonio Napolitano
- Medical Physics Department, Enterprise Risk Management, Bambino Gesù Children's Hospital, Rome, Lazio, Italy
| |
Collapse
|
257
|
Examination of Local Functional Homogeneity in Autism. BIOMED RESEARCH INTERNATIONAL 2015; 2015:174371. [PMID: 26180782 PMCID: PMC4477064 DOI: 10.1155/2015/174371] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/09/2014] [Indexed: 01/07/2023]
Abstract
Increasing neuroimaging evidence suggests that autism patients exhibit abnormal brain structure and function. We used the Autism Brain Imaging Data Exchange (ABIDE) sample to analyze locally focal (~8 mm) functional connectivity of 223 autism patients and 285 normal controls from 15 international sites using a recently developed surface-based approach. We observed enhanced local connectivity in the middle frontal cortex, left precuneus, and right superior temporal sulcus, and reduced local connectivity in the right insular cortex. The local connectivity in the right middle frontal gyrus was positively correlated with the total score of the autism diagnostic observation schedule whereas the local connectivity within the right superior temporal sulcus was positively correlated with total subscores of both the communication and the stereotyped behaviors and restricted interests of the schedule. Finally, significant interactions between age and clinical diagnosis were detected in the left precuneus. These findings replicated previous observations that used a volume-based approach and suggested possible neuropathological impairments of local information processing in the frontal, temporal, parietal, and insular cortices. Novel site-variability analysis demonstrated high reproducibility of our findings across the 15 international sites. The age-disease interaction provides a potential target region for future studies to further elucidate the neurodevelopmental mechanisms of autism.
Collapse
|
258
|
Abnormal resting state FMRI activity predicts processing speed deficits in first-episode psychosis. Neuropsychopharmacology 2015; 40:1631-9. [PMID: 25567423 PMCID: PMC4915267 DOI: 10.1038/npp.2015.7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 01/10/2023]
Abstract
Little is known regarding the neuropsychological significance of resting state functional magnetic resonance imaging (rs-fMRI) activity early in the course of psychosis. Moreover, no studies have used different approaches for analysis of rs-fMRI activity and examined gray matter thickness in the same cohort. In this study, 41 patients experiencing a first-episode of psychosis (including N=17 who were antipsychotic drug-naive at the time of scanning) and 41 individually age- and sex-matched healthy volunteers completed rs-fMRI and structural MRI exams and neuropsychological assessments. We computed correlation matrices for 266 regions-of-interest across the brain to assess global connectivity. In addition, independent component analysis (ICA) was used to assess group differences in the expression of rs-fMRI activity within 20 predefined publicly available templates. Patients demonstrated lower overall rs-fMRI global connectivity compared with healthy volunteers without associated group differences in gray matter thickness assessed within the same regions-of-interest used in this analysis. Similarly, ICA revealed worse rs-fMRI expression scores across all 20 networks in patients compared with healthy volunteers, with posthoc analyses revealing significant (p<0.05; corrected) abnormalities within the caudate nucleus and planum temporale. Worse processing speed correlated significantly with overall lower global connectivity using the region-of-interest approach and lower expression scores within the planum temporale using ICA. Our findings implicate dysfunction in rs-fMRI activity in first-episode psychosis prior to extensive antipsychotic treatment using different analytic approaches (in the absence of concomitant gray matter structural differences) that predict processing speed.
Collapse
|
259
|
Solana AB, Martínez K, Hernández-Tamames JA, San Antonio-Arce V, Toledano R, García-Morales I, Alvárez-Linera J, Gil-Nágel A, Del Pozo F. Altered brain rhythms and functional network disruptions involved in patients with generalized fixation-off epilepsy. Brain Imaging Behav 2015; 10:373-86. [PMID: 26001771 DOI: 10.1007/s11682-015-9404-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Generalized Fixation-off Sensitivity (CGE-FoS) patients present abnormal EEG patterns when losing fixation. In the present work, we studied two CGE-FoS epileptic patients with simultaneous EEG-fMRI. We aim to identify brain areas that are specifically related to the pathology by identifying the brain networks that are related to the EEG brain altered rhythms. Three main analyses were performed: EEG standalone, where the voltage fluctuations in delta, alpha, and beta EEG bands were obtained; fMRI standalone, where resting-state fMRI ICA analyses for opened and closed eyes conditions were computed per subject; and, EEG-informed fMRI, where EEG delta, alpha and beta oscillations were used to analyze fMRI. Patient 1 showed EEG abnormalities for lower beta band EEG brain rhythm. Fluctuations of this rhythm were correlated with a brain network mainly composed by temporo-frontal areas only found in the closed eyes condition. Patient 2 presented alterations in all the EEG brain rhythms (delta, alpha, beta) under study when closing eyes. Several biologically relevant brain networks highly correlated (r > 0.7) to each other in the closed eyes condition were found. EEG-informed fMRI results in patient 2 showed hypersynchronized patterns in the fMRI correlation spatial maps. The obtained findings allow a differential diagnosis for each patient and different profiles with respect to healthy volunteers. The results suggest a different disruption in the functional brain networks of these patients that depends on their altered brain rhythms. This knowledge could be used to treat these patients by novel brain stimulation approaches targeting specific altered brain networks in each patient.
Collapse
Affiliation(s)
- Ana Beatriz Solana
- Department of Neuroimaging, Center for Biomedical Technology, Universidad Politécnica de Madrid, Autopista M40 Km.38, 28223, Pozuelo de Alarcón, Spain. .,GE Global Research, Freisinger Landstrasse 50, 85748, Garching bei Munich, Bayern, Germany.
| | - Kenia Martínez
- Research Unit, Instituto de Investigación Sanitaria del Hospital Gregorio Marañón (IISGM), Calle Doctor Esquerdo, 46, 28007, Madrid, Spain
| | | | | | - Rafael Toledano
- Department of Neurology, Hospital Ruber Internacional, Calle de la Maso, 38, 28034, Madrid, Spain
| | - Irene García-Morales
- Department of Neurology, Hospital Ruber Internacional, Calle de la Maso, 38, 28034, Madrid, Spain
| | - Juan Alvárez-Linera
- Department of Neuroradiology, Hospital Ruber Internacional, Calle de la Maso, 38, 28034, Madrid, Spain
| | - Antonio Gil-Nágel
- Department of Neurology, Hospital Ruber Internacional, Calle de la Maso, 38, 28034, Madrid, Spain
| | - Francisco Del Pozo
- Department of Neuroimaging, Center for Biomedical Technology, Universidad Politécnica de Madrid, Autopista M40 Km.38, 28223, Pozuelo de Alarcón, Spain
| |
Collapse
|
260
|
Birn RM, Cornejo MD, Molloy EK, Patriat R, Meier TB, Kirk GR, Nair VA, Meyerand ME, Prabhakaran V. The influence of physiological noise correction on test-retest reliability of resting-state functional connectivity. Brain Connect 2015; 4:511-22. [PMID: 25112809 DOI: 10.1089/brain.2014.0284] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The utility and success of resting-state functional connectivity MRI (rs-fcMRI) depend critically on the reliability of this technique and the extent to which it accurately reflects neuronal function. One challenge is that rs-fcMRI is influenced by various sources of noise, particularly cardiac- and respiratory-related signal variations. The goal of the current study was to evaluate the impact of various physiological noise correction techniques, specifically those that use independent cardiac and respiration measures, on the test-retest reliability of rs-fcMRI. A group of 25 subjects were each scanned at three time points--two within the same imaging session and another 2-3 months later. Physiological noise corrections accounted for significant variance, particularly in blood vessels, sagittal sinus, cerebrospinal fluid, and gray matter. The fraction of variance explained by each of these corrections was highly similar within subjects between sessions, but variable between subjects. Physiological corrections generally reduced intrasubject (between-session) variability, but also significantly reduced intersubject variability, and thus reduced the test-retest reliability of estimating individual differences in functional connectivity. However, based on known nonneuronal mechanisms by which cardiac pulsation and respiration can lead to MRI signal changes, and the observation that the physiological noise itself is highly stable within individuals, removal of this noise will likely increase the validity of measured connectivity differences. Furthermore, removal of these fluctuations will lead to better estimates of average or group maps of connectivity. It is therefore recommended that studies apply physiological noise corrections but also be mindful of potential correlations with measures of interest.
Collapse
Affiliation(s)
- Rasmus M Birn
- 1 Department of Psychiatry, University of Wisconsin-Madison , Madison, Wisconsin
| | | | | | | | | | | | | | | | | |
Collapse
|
261
|
Agreement and repeatability of vascular reactivity estimates based on a breath-hold task and a resting state scan. Neuroimage 2015; 113:387-96. [PMID: 25795342 PMCID: PMC4441043 DOI: 10.1016/j.neuroimage.2015.03.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 02/27/2015] [Accepted: 03/03/2015] [Indexed: 12/02/2022] Open
Abstract
FMRI BOLD responses to changes in neural activity are influenced by the reactivity of the vasculature. By complementing a task-related BOLD acquisition with a vascular reactivity measure obtained through breath-holding or hypercapnia, this unwanted variance can be statistically reduced in the BOLD responses of interest. Recently, it has been suggested that vascular reactivity can also be estimated using a resting state scan. This study aimed to compare three breath-hold based analysis approaches (block design, sine–cosine regressor and CO2 regressor) and a resting state approach (CO2 regressor) to measure vascular reactivity. We tested BOLD variance explained by the model and repeatability of the measures. Fifteen healthy participants underwent a breath-hold task and a resting state scan with end-tidal CO2 being recorded during both. Vascular reactivity was defined as CO2-related BOLD percent signal change/mm Hg change in CO2. Maps and regional vascular reactivity estimates showed high repeatability when the breath-hold task was used. Repeatability and variance explained by the CO2 trace regressor were lower for the resting state data based approach, which resulted in highly variable measures of vascular reactivity. We conclude that breath-hold based vascular reactivity estimations are more repeatable than resting-based estimates, and that there are limitations with replacing breath-hold scans by resting state scans for vascular reactivity assessment.
Collapse
|
262
|
Zhang D, Liang B, Wu X, Wang Z, Xu P, Chang S, Liu B, Liu M, Huang R. Directionality of large-scale resting-state brain networks during eyes open and eyes closed conditions. Front Hum Neurosci 2015; 9:81. [PMID: 25745394 PMCID: PMC4333775 DOI: 10.3389/fnhum.2015.00081] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 02/02/2015] [Indexed: 11/13/2022] Open
Abstract
The present study examined directional connections in the brain among resting-state networks (RSNs) when the participant had their eyes open (EO) or had their eyes closed (EC). The resting-state fMRI data were collected from 20 healthy participants (9 males, 20.17 ± 2.74 years) under the EO and EC states. Independent component analysis (ICA) was applied to identify the separated RSNs (i.e., the primary/high-level visual, primary sensory-motor, ventral motor, salience/dorsal attention, and anterior/posterior default-mode networks), and the Gaussian Bayesian network (BN) learning approach was then used to explore the conditional dependencies among these RSNs. The network-to-network directional connections related to EO and EC were depicted, and a support vector machine (SVM) was further employed to identify the directional connection patterns that could effectively discriminate between the two states. The results indicated that the connections among RSNs are directionally connected within a BN during the EO and EC states. The directional connections from the salience network (SN) to the anterior/posterior default-mode networks and the high-level to primary-level visual network were the obvious characteristics of both the EO and EC resting-state BNs. Of the directional connections in BN, the directional connections of the salience and dorsal attention network (DAN) were observed to be discriminative between the EO and EC states. In particular, we noted that the properties of the salience and DANs were in opposite directions. Overall, the present study described the directional connections of RSNs using a BN learning approach during the EO and EC states, and the results suggested that the directionality of the attention systems (i.e., mainly for the salience and the DAN) in resting state might have important roles in switching between the EO and EC conditions.
Collapse
Affiliation(s)
- Delong Zhang
- Department of Radiology, Guangdong Provincial Hospital of Chinese Medicine Guangzhou, China ; Guangzhou University of Chinese Medicine Postdoctoral Mobile Research Station Guangzhou, China
| | - Bishan Liang
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University Guangzhou, China
| | - Xia Wu
- School of Information Science and Technology, Beijing Normal University Beijing, China
| | - Zengjian Wang
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University Guangzhou, China
| | - Pengfei Xu
- Institute of Affective and Social Neuroscience, Shenzhen University Shenzhen, China ; Neuroimaging Center, University Medical Center Groningen, University of Groningen Groningen, Netherlands ; National Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University Beijing, China
| | - Song Chang
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University Guangzhou, China
| | - Bo Liu
- Department of Radiology, Guangdong Provincial Hospital of Chinese Medicine Guangzhou, China
| | - Ming Liu
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University Guangzhou, China
| | - Ruiwang Huang
- Center for the Study of Applied Psychology, Key Laboratory of Mental Health and Cognitive Science of Guangdong Province, School of Psychology, South China Normal University Guangzhou, China
| |
Collapse
|
263
|
Chien HY, Lin HY, Lai MC, Gau SSF, Tseng WYI. Hyperconnectivity of the Right Posterior Temporo-parietal Junction Predicts Social Difficulties in Boys with Autism Spectrum Disorder. Autism Res 2015; 8:427-41. [DOI: 10.1002/aur.1457] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 11/25/2014] [Indexed: 01/13/2023]
Affiliation(s)
- Hsiang-Yun Chien
- From the Department of Psychiatry; National Taiwan University Hospital; Taipei Taiwan
- Center for Optoelectronic Medicine, College of Medicine; National Taiwan University; Taipei Taiwan
| | - Hsiang-Yuan Lin
- From the Department of Psychiatry; National Taiwan University Hospital; Taipei Taiwan
| | - Meng-Chuan Lai
- From the Department of Psychiatry; National Taiwan University Hospital; Taipei Taiwan
- Autism Research Centre, Department of Psychiatry; University of Cambridge; Cambridge United Kingdom
- Department of Psychiatry; National Taiwan University College of Medicine; Taipei Taiwan
| | - Susan Shur-Fen Gau
- From the Department of Psychiatry; National Taiwan University Hospital; Taipei Taiwan
- Department of Psychiatry; National Taiwan University College of Medicine; Taipei Taiwan
- Graduate Institute of Brain and Mind Sciences; National Taiwan University College of Medicine; Taipei Taiwan
| | - Wen-Yih Isaac Tseng
- Center for Optoelectronic Medicine, College of Medicine; National Taiwan University; Taipei Taiwan
- Graduate Institute of Brain and Mind Sciences; National Taiwan University College of Medicine; Taipei Taiwan
| |
Collapse
|
264
|
Abstract
Autism spectrum disorder (ASD) affects 1 in 50 children between the ages of 6 and 17 years. The etiology of ASD is not precisely known. ASD is an umbrella term, which includes both low- (IQ < 70) and high-functioning (IQ > 70) individuals. A better understanding of the disorder and how it manifests in individual subjects can lead to more effective intervention plans to fulfill the individual's treatment needs.Magnetic resonance imaging (MRI) is a non-invasive investigational tool that can be used to study the ways in which the brain develops or deviates from the typical developmental trajectory. MRI offers insights into the structure, function, and metabolism of the brain. In this article, we review published studies on brain connectivity changes in ASD using either resting state functional MRI or diffusion tensor imaging.The general findings of decreases in white matter integrity and in long-range neural coherence are well known in the ASD literature. Nevertheless, the detailed localization of these findings remains uncertain, and few studies link these changes in connectivity with the behavioral phenotype of the disorder. With the help of data sharing and large-scale analytic efforts, however, the field is advancing toward several convergent themes, including the reduced functional coherence of long-range intra-hemispheric cortico-cortical default mode circuitry, impaired inter-hemispheric regulation, and an associated, perhaps compensatory, increase in local and short-range cortico-subcortical coherence.
Collapse
|
265
|
de Kwaasteniet BP, Rive MM, Ruhé HG, Schene AH, Veltman DJ, Fellinger L, van Wingen GA, Denys D. Decreased Resting-State Connectivity between Neurocognitive Networks in Treatment Resistant Depression. Front Psychiatry 2015; 6:28. [PMID: 25784881 PMCID: PMC4345766 DOI: 10.3389/fpsyt.2015.00028] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 02/09/2015] [Indexed: 12/28/2022] Open
Abstract
Approximately one-third of patients with major depressive disorder (MDD) do not achieve remission after various treatment options and develop treatment resistant depression (TRD). So far, little is known about the pathophysiology of TRD. Studies in MDD patients showed aberrant functional connectivity (FC) of three "core" neurocognitive networks: the salience network (SN), cognitive control network (CCN), and default mode network (DMN). We used a cross-sectional design and performed resting-state FC MRI to assess connectivity of the SN, CCN, and both anterior and posterior DMN in 17 severe TRD, 18 non-TRD, and 18 healthy control (HC) subjects. Relative to both non-TRD and HC subjects, TRD patients showed decreased FC between the dorsolateral prefrontal cortex and angular gyrus, which suggests reduced FC between the CCN and DMN, and reduced FC between the medial prefrontal cortex and precuneus/cuneus, which suggests reduced FC between the anterior and posterior DMN. No significant differences in SN FC were observed. Our results suggest that TRD is characterized by a disturbance in neurocognitive networks relative to non-TRD and HC.
Collapse
Affiliation(s)
- Bart P de Kwaasteniet
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands
| | - Maria M Rive
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands
| | - Henricus G Ruhé
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands ; Department of Psychiatry, Mood and Anxiety Disorders, University Medical Center Groningen, University of Groningen , Groningen , Netherlands
| | - Aart H Schene
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Department of Psychiatry, Radboud University Medical Center , Nijmegen , Netherlands ; Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen , Nijmegen , Netherlands
| | - Dick J Veltman
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Department of Psychiatry, VU University Medical Center , Amsterdam , Netherlands
| | - Lisanne Fellinger
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands
| | - Guido A van Wingen
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands
| | - Damiaan Denys
- Department of Psychiatry, Academic Medical Center , Amsterdam , Netherlands ; Brain Imaging Center, Academic Medical Center , Amsterdam , Netherlands ; Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences , Amsterdam , Netherlands
| |
Collapse
|
266
|
Bortoletto M, Veniero D, Thut G, Miniussi C. The contribution of TMS-EEG coregistration in the exploration of the human cortical connectome. Neurosci Biobehav Rev 2014; 49:114-24. [PMID: 25541459 DOI: 10.1016/j.neubiorev.2014.12.014] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 10/14/2014] [Accepted: 12/11/2014] [Indexed: 12/14/2022]
Abstract
Recent developments in neuroscience have emphasised the importance of integrated distributed networks of brain areas for successful cognitive functioning. Our current understanding is that the brain has a modular organisation in which segregated networks supporting specialised processing are linked through a few long-range connections, ensuring processing integration. Although such architecture is structurally stable, it appears to be flexible in its functioning, enabling long-range connections to regulate the information flow and facilitate communication among the relevant modules, depending on the contingent cognitive demands. Here we show how insights brought by the coregistration of transcranial magnetic stimulation and electroencephalography (TMS-EEG) integrate and support recent models of functional brain architecture. Moreover, we will highlight the types of data that can be obtained through TMS-EEG, such as the timing of signal propagation, the excitatory/inhibitory nature of connections and causality. Last, we will discuss recent emerging applications of TMS-EEG in the study of brain disorders.
Collapse
Affiliation(s)
- Marta Bortoletto
- Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
| | - Domenica Veniero
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK
| | - Carlo Miniussi
- Cognitive Neuroscience Section, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; Neuroscience Section, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| |
Collapse
|
267
|
Caciagli L, Bernhardt BC, Hong SJ, Bernasconi A, Bernasconi N. Functional network alterations and their structural substrate in drug-resistant epilepsy. Front Neurosci 2014; 8:411. [PMID: 25565942 PMCID: PMC4263093 DOI: 10.3389/fnins.2014.00411] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/24/2014] [Indexed: 12/24/2022] Open
Abstract
The advent of MRI has revolutionized the evaluation and management of drug-resistant epilepsy by allowing the detection of the lesion associated with the region that gives rise to seizures. Recent evidence indicates marked chronic alterations in the functional organization of lesional tissue and large-scale cortico-subcortical networks. In this review, we focus on recent methodological developments in functional MRI (fMRI) analysis techniques and their application to the two most common drug-resistant focal epilepsies, i.e., temporal lobe epilepsy related to mesial temporal sclerosis and extra-temporal lobe epilepsy related to focal cortical dysplasia. We put particular emphasis on methodological developments in the analysis of task-free or “resting-state” fMRI to probe the integrity of intrinsic networks on a regional, inter-regional, and connectome-wide level. In temporal lobe epilepsy, these techniques have revealed disrupted connectivity of the ipsilateral mesiotemporal lobe, together with contralateral compensatory reorganization and striking reconfigurations of large-scale networks. In cortical dysplasia, initial observations indicate functional alterations in lesional, peri-lesional, and remote neocortical regions. While future research is needed to critically evaluate the reliability, sensitivity, and specificity, fMRI mapping promises to lend distinct biomarkers for diagnosis, presurgical planning, and outcome prediction.
Collapse
Affiliation(s)
- Lorenzo Caciagli
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University Montreal, QC, Canada
| | - Boris C Bernhardt
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University Montreal, QC, Canada
| | - Seok-Jun Hong
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University Montreal, QC, Canada
| | - Andrea Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University Montreal, QC, Canada
| | - Neda Bernasconi
- Neuroimaging of Epilepsy Laboratory, McConnell Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University Montreal, QC, Canada
| |
Collapse
|
268
|
Jann K, Gee DG, Kilroy E, Schwab S, Smith RX, Cannon TD, Wang DJJ. Functional connectivity in BOLD and CBF data: similarity and reliability of resting brain networks. Neuroimage 2014; 106:111-22. [PMID: 25463468 DOI: 10.1016/j.neuroimage.2014.11.028] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 11/03/2014] [Accepted: 11/14/2014] [Indexed: 11/25/2022] Open
Abstract
Resting-state functional connectivity (FC) fMRI (rs-fcMRI) offers an appealing approach to mapping the brain's intrinsic functional organization. Blood oxygen level dependent (BOLD) and arterial spin labeling (ASL) are the two main rs-fcMRI approaches to assess alterations in brain networks associated with individual differences, behavior and psychopathology. While the BOLD signal is stronger with a higher temporal resolution, ASL provides quantitative, direct measures of the physiology and metabolism of specific networks. This study systematically investigated the similarity and reliability of resting brain networks (RBNs) in BOLD and ASL. A 2 × 2 × 2 factorial design was employed where each subject underwent repeated BOLD and ASL rs-fcMRI scans on two occasions on two MRI scanners respectively. Both independent and joint FC analyses revealed common RBNs in ASL and BOLD rs-fcMRI with a moderate to high level of spatial overlap, verified by Dice Similarity Coefficients. Test-retest analyses indicated more reliable spatial network patterns in BOLD (average modal Intraclass Correlation Coefficients: 0.905 ± 0.033 between-sessions; 0.885 ± 0.052 between-scanners) than ASL (0.545 ± 0.048; 0.575 ± 0.059). Nevertheless, ASL provided highly reproducible (0.955 ± 0.021; 0.970 ± 0.011) network-specific CBF measurements. Moreover, we observed positive correlations between regional CBF and FC in core areas of all RBNs indicating a relationship between network connectivity and its baseline metabolism. Taken together, the combination of ASL and BOLD rs-fcMRI provides a powerful tool for characterizing the spatiotemporal and quantitative properties of RBNs. These findings pave the way for future BOLD and ASL rs-fcMRI studies in clinical populations that are carried out across time and scanners.
Collapse
Affiliation(s)
- Kay Jann
- Department of Neurology, UCLA, 90025 Los Angeles, USA.
| | - Dylan G Gee
- Department of Psychology, UCLA, 90025 Los Angeles, USA
| | - Emily Kilroy
- Department of Neurology, UCLA, 90025 Los Angeles, USA
| | - Simon Schwab
- Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, University Bern, 3000 Bern 60, Switzerland
| | | | - Tyrone D Cannon
- Department of Psychology, Yale University, 06520 New Haven, USA
| | | |
Collapse
|
269
|
Abstract
In recent years, some substantial advances in understanding human (and nonhuman) brain organization have emerged from a relatively unusual approach: the observation of spontaneous activity, and correlated patterns in spontaneous activity, in the "resting" brain. Most commonly, spontaneous neural activity is measured indirectly via fMRI signal in subjects who are lying quietly in the scanner, the so-called "resting state." This Primer introduces the fMRI-based study of spontaneous brain activity, some of the methodological issues active in the field, and some ways in which resting-state fMRI has been used to delineate aspects of area-level and supra-areal brain organization.
Collapse
Affiliation(s)
- Jonathan D Power
- Department of Neurology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
| | - Bradley L Schlaggar
- Department of Neurology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Pediatrics, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Anatomy & Neurobiology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Steven E Petersen
- Department of Neurology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Radiology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Anatomy & Neurobiology, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Psychology, Washington University in Saint Louis, One Brookings Drive, St. Louis, MO 63130, USA; Department of Neurosurgery, Washington University School of Medicine in St. Louis, 660 S. Euclid Avenue, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University in Saint Louis, One Brookings Drive, St. Louis, MO 63130, USA
| |
Collapse
|
270
|
Compact and informative representation of functional connectivity for predictive modeling. MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION : MICCAI ... INTERNATIONAL CONFERENCE ON MEDICAL IMAGE COMPUTING AND COMPUTER-ASSISTED INTERVENTION 2014. [PMID: 25320794 DOI: 10.1007/978-3-319-10443-0_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Resting state functional connectivity holds great potential for diagnostic prediction of neurological and psychiatric illness. This paper introduces a compact and information-rich representation of connectivity that is geared directly towards predictive modeling. Our representation does not require a priori identification of localized regions of interest, yet provides a mechanism for interpretation of classifier weights. Experiments confirm increased accuracy associated with our representation and yield interpretations consistent with known physiology.
Collapse
|
271
|
Kohn N, Wassenberg A, Toygar T, Kellermann T, Weidenfeld C, Berthold-Losleben M, Chechko N, Orfanos S, Vocke S, Laoutidis ZG, Schneider F, Karges W, Habel U. Prolonged fasting impairs neural reactivity to visual stimulation. Brain Struct Funct 2014; 221:147-58. [DOI: 10.1007/s00429-014-0898-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/19/2014] [Indexed: 10/24/2022]
|
272
|
Liu Z, Guo H, Cao X, Cheng C, Yang C, Xu C, Zhang A, Sun N, Li X, Zhang K. A combined study of GSK3β polymorphisms and brain network topological metrics in major depressive disorder. Psychiatry Res 2014; 223:210-7. [PMID: 24994693 DOI: 10.1016/j.pscychresns.2014.05.010] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 05/02/2014] [Accepted: 05/16/2014] [Indexed: 12/15/2022]
Abstract
GSK3β genotypes may interact with major depressive disorder (MDD) and may have a role in determining regional gray matter volume differences from healthy comparison subjects. However, any associations of GSK3β genotypes with MDD related to abnormal functional brain activity have yet to be elucidated. In the present study, resting state functional brain networks were constructed by thresholding partial correlation matrices of 90 regions. Differences in the network features of GSK3β-rs6438552 genotypes were tested, and a 2×2 analysis of variance was performed to identify the main effects of genotypes, disease status, and their interactions in MDD. Compared with CC carriers, T+ carriers with MDD showed increased nodal centralities in many brain regions-mainly the limbic system, thalamus and parts of the parietal, temporal, occipital, and frontal regions. Decreased nodal centralities predominantly occurred in the sensorimotor area and parts of the frontal, occipital, and temporal lobes. Significant interactions between genotypes and disease status were found in the left thalamus, left superior occipital gyrus, and left inferior parietal lobe. Only altered nodal centrality in the left angular gyrus was negatively correlated with scores on the Hamilton Depression Rating Scale. Our results suggest the GSK3β genotypic effect of rs6438552 and its interaction with disease status may contribute to the altered topological organization of resting state functional brain networks in MDD patients.
Collapse
Affiliation(s)
- Zhifen Liu
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Hao Guo
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan 030024, PR China
| | - Xiaohua Cao
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Chen Cheng
- College of Computer Science and Technology, Taiyuan University of Technology, Taiyuan 030024, PR China
| | - Chunxia Yang
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Cheng Xu
- Department of Radiology, Shanxi Provincial Hospital, Taiyuan 030012, PR China
| | - Aixia Zhang
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Ning Sun
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Xinrong Li
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China
| | - Kerang Zhang
- Department of Psychiatry, First Hospital of Shanxi Medical University, Taiyuan 030001, PR China.
| |
Collapse
|
273
|
Jia H, Hu X, Deshpande G. Behavioral relevance of the dynamics of the functional brain connectome. Brain Connect 2014; 4:741-59. [PMID: 25163490 DOI: 10.1089/brain.2014.0300] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
While many previous studies assumed the functional connectivity (FC) between brain regions to be stationary, recent studies have demonstrated that FC dynamically varies across time. However, two challenges have limited the interpretability of dynamic FC information. First, a principled framework for selecting the temporal extent of the window used to examine the dynamics is lacking and this has resulted in ad-hoc selections of window lengths and subsequent divergent results. Second, it is unclear whether there is any behavioral relevance to the dynamics of the functional connectome in addition to that obtained from conventional static FC (SFC). In this work, we address these challenges by first proposing a principled framework for selecting the extent of the temporal windows in a dynamic and data-driven fashion based on statistical tests of the stationarity of time series. Further, we propose a method involving three levels of clustering-across space, time, and subjects-which allow for group-level inferences of the dynamics. Next, using a large resting-state functional magnetic resonance imaging and behavioral dataset from the Human Connectome Project, we demonstrate that metrics derived from dynamic FC can explain more than twice the variance in 75 behaviors across different domains (alertness, cognition, emotion, and personality traits) as compared with SFC in healthy individuals. Further, we found that individuals with brain networks exhibiting greater dynamics performed more favorably in behavioral tasks. This indicates that the ease with which brain regions engage or disengage may provide potential biomarkers for disorders involving altered neural circuitry.
Collapse
Affiliation(s)
- Hao Jia
- 1 Department of Electrical and Computer Engineering, AU MRI Research Center, Auburn University , Auburn, Alabama
| | | | | |
Collapse
|
274
|
Barkhof F, Haller S, Rombouts SARB. Resting-state functional MR imaging: a new window to the brain. Radiology 2014; 272:29-49. [PMID: 24956047 DOI: 10.1148/radiol.14132388] [Citation(s) in RCA: 250] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Resting-state (RS) functional magnetic resonance (MR) imaging constitutes a novel paradigm that examines spontaneous brain function by using blood oxygen level-dependent contrast in the absence of a task. Spatially distributed networks of temporal synchronization can be detected that can characterize RS networks (RSNs). With a short acquisition time of less than 10 minutes, RS functional MR imaging can be applied in special populations such as children and patients with dementia. Some RSNs are already present in utero, while others mature in childhood. Around 10 major RSNs are consistently found in adults, but their exact spatial extent and strength of coherence are affected by physiologic parameters and drugs. Though the acquisition and analysis methods are still evolving, new disease insights are emerging in a variety of neurologic and psychiatric disorders. The default mode network is affected in Alzheimer disease and various other diseases of cognitive impairment. Alterations in RSNs have been identified in many diseases, in the absence of evident structural modifications, indicating a high sensitivity of the method. Moreover, there is evidence of correlation between RSN alterations and disease progression and severity. However, different diseases often affect the same RSN, illustrating the limited specificity of the findings. This suggests that neurologic and psychiatric diseases are characterized by altered interactions between RSNs and therefore the whole brain should be examined as an integral network (with subnetworks), for example, using graph analysis. A challenge for clinical applications of RS functional MR imaging is the potentially confounding effect of aging, concomitant vascular diseases, or medication on the neurovascular coupling and consequently the functional MR imaging response. Current investigation combines RS functional MR imaging and other methods such as electroencephalography or magnetoencephalography to better understand the vascular and neuronal contributions to alterations in functional connectivity.
Collapse
Affiliation(s)
- Frederik Barkhof
- From the Department of Radiology and Nuclear Medicine, Neuroscience Campus Amsterdam, VU University Medical Centre, PO Box 7057, 1007 MB Amsterdam, the Netherlands (F.B.); Service neuro-diagnostique et neuro-interventionnel DISIM, University Hospitals of Geneva, Geneva, Switzerland (S.H.); and Department of Radiology, Leiden University Medical Center and Institute of Psychology, Leiden University, Leiden, the Netherlands (S.A.R.B.R.)
| | | | | |
Collapse
|
275
|
Robust brain parcellation using sparse representation on resting-state fMRI. Brain Struct Funct 2014; 220:3565-79. [PMID: 25156576 PMCID: PMC4575697 DOI: 10.1007/s00429-014-0874-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 08/07/2014] [Indexed: 11/13/2022]
Abstract
Resting-state fMRI (rs-fMRI) has been widely used to segregate the brain into individual modules based on the presence of distinct connectivity patterns. Many parcellation methods have been proposed for brain parcellation using rs-fMRI, but their results have been somewhat inconsistent, potentially due to various types of noise. In this study, we provide a robust parcellation method for rs-fMRI-based brain parcellation, which constructs a sparse similarity graph based on the sparse representation coefficients of each seed voxel and then uses spectral clustering to identify distinct modules. Both the local time-varying BOLD signals and whole-brain connectivity patterns may be used as features and yield similar parcellation results. The robustness of our method was tested on both simulated and real rs-fMRI datasets. In particular, on simulated rs-fMRI data, sparse representation achieved good performance across different noise levels, including high accuracy of parcellation and high robustness to noise. On real rs-fMRI data, stable parcellation of the medial frontal cortex (MFC) and parietal operculum (OP) were achieved on three different datasets, with high reproducibility within each dataset and high consistency across these results. Besides, the parcellation of MFC was little influenced by the degrees of spatial smoothing. Furthermore, the consistent parcellation of OP was also well corresponding to cytoarchitectonic subdivisions and known somatotopic organizations. Our results demonstrate a new promising approach to robust brain parcellation using resting-state fMRI by sparse representation.
Collapse
|
276
|
Rajab AS, Crane DE, Middleton LE, Robertson AD, Hampson M, MacIntosh BJ. A single session of exercise increases connectivity in sensorimotor-related brain networks: a resting-state fMRI study in young healthy adults. Front Hum Neurosci 2014; 8:625. [PMID: 25177284 PMCID: PMC4132485 DOI: 10.3389/fnhum.2014.00625] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 07/26/2014] [Indexed: 11/13/2022] Open
Abstract
Habitual long term physical activity is known to have beneficial cognitive, structural, and neuro-protective brain effects, but to date there is limited knowledge on whether a single session of exercise can alter the brain's functional connectivity, as assessed by resting-state functional magnetic resonance imaging (rs-fMRI). The primary objective of this study was to characterize potential session effects in resting-state networks (RSNs). We examined the acute effects of exercise on the functional connectivity of young healthy adults (N = 15) by collecting rs-fMRI before and after 20 min of moderate intensity aerobic exercise and compared this with a no-exercise control group (N = 15). Data were analyzed using independent component analysis, denoising and dual regression procedures. Regions of interest-based group session effect statistics were calculated in RSNs of interest using voxel-wise permutation testing and Cohen's D effect size. Group analysis in the exercising group data set revealed a session effect in sub-regions of three sensorimotor related areas: the pre and/or postcentral gyri, secondary somatosensory area and thalamus, characterized by increased co-activation after exercise (corrected p < 0.05). Cohen's D analysis also showed a significant effect of session in these three RSNs (p< 0.05), corroborating the voxel-wise findings. Analyses of the no-exercise dataset produced no significant results, thereby providing support for the exercise findings and establishing the inherent test-retest reliability of the analysis pipeline on the RSNs of interest. This study establishes the feasibility of rs-fMRI to localize brain regions that are associated with acute exercise, as well as an analysis consideration to improve sensitivity to a session effect.
Collapse
Affiliation(s)
- Ahmad S Rajab
- Department of Medical Biophysics, University of Toronto Toronto ON, Canada ; Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute Toronto, ON, Canada
| | - David E Crane
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute Toronto, ON, Canada
| | - Laura E Middleton
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute Toronto, ON, Canada ; Department of Kinesiology, University of Waterloo Waterloo, ON, Canada
| | - Andrew D Robertson
- Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute Toronto, ON, Canada
| | - Michelle Hampson
- Department of Diagnostic Radiology, Yale University School of Medicine New Haven, CT, USA
| | - Bradley J MacIntosh
- Department of Medical Biophysics, University of Toronto Toronto ON, Canada ; Heart and Stroke Foundation Canadian Partnership for Stroke Recovery, Sunnybrook Research Institute Toronto, ON, Canada
| |
Collapse
|
277
|
Becerra L, Sava S, Simons LE, Drosos AM, Sethna N, Berde C, Lebel AA, Borsook D. Intrinsic brain networks normalize with treatment in pediatric complex regional pain syndrome. Neuroimage Clin 2014; 6:347-69. [PMID: 25379449 PMCID: PMC4218937 DOI: 10.1016/j.nicl.2014.07.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Revised: 07/17/2014] [Accepted: 07/29/2014] [Indexed: 12/22/2022]
Abstract
Pediatric complex regional pain syndrome (P-CRPS) offers a unique model of chronic neuropathic pain as it either resolves spontaneously or through therapeutic interventions in most patients. Here we evaluated brain changes in well-characterized children and adolescents with P-CRPS by measuring resting state networks before and following a brief (median = 3 weeks) but intensive physical and psychological treatment program, and compared them to matched healthy controls. Differences in intrinsic brain networks were observed in P-CRPS compared to controls before treatment (disease state) with the most prominent differences in the fronto-parietal, salience, default mode, central executive, and sensorimotor networks. Following treatment, behavioral measures demonstrated a reduction of symptoms and improvement of physical state (pain levels and motor functioning). Correlation of network connectivities with spontaneous pain measures pre- and post-treatment indicated concomitant reductions in connectivity in salience, central executive, default mode and sensorimotor networks (treatment effects). These results suggest a rapid alteration in global brain networks with treatment and provide a venue to assess brain changes in CRPS pre- and post-treatment, and to evaluate therapeutic effects.
Collapse
Affiliation(s)
- Lino Becerra
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA ; Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA ; Department of Radiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Simona Sava
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Laura E Simons
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA ; Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Athena M Drosos
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Navil Sethna
- Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Charles Berde
- Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - Alyssa A Lebel
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA ; Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| | - David Borsook
- Pain/Analgesia Imaging Neuroscience (P.A.I.N.) Group, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA ; Department of Anesthesiology, Boston Children's Hospital, 300 Longwood Ave., Boston, MA 02115, USA
| |
Collapse
|
278
|
Yuan BK, Wang J, Zang YF, Liu DQ. Amplitude differences in high-frequency fMRI signals between eyes open and eyes closed resting states. Front Hum Neurosci 2014; 8:503. [PMID: 25071530 PMCID: PMC4086401 DOI: 10.3389/fnhum.2014.00503] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 06/23/2014] [Indexed: 01/04/2023] Open
Abstract
Recent studies employing rapid sampling techniques have demonstrated that the resting state fMRI (rs-fMRI) signal exhibits synchronized activities at frequencies much higher than the conventional frequency range (<0.1 Hz). However, little work has investigated the changes in the high-frequency fluctuations between different resting states. Here, we acquired rs-fMRI data at a high sampling rate (TR = 400 ms) from subjects with both eyes open (EO) and eyes closed (EC), and compared the amplitude of fluctuation (AF) between EO and EC for both the low- and high-frequency components. In addition to robust AF differences in the conventional low frequency band (<0.1 Hz) in visual cortex, primary auditory cortex and primary sensorimotor cortex (PSMC), we also detected high-frequency (primarily in 0.1–0.35 Hz) differences. The high-frequency results without covariates regression exhibited noisy patterns. For the data with nuisance covariates regression, we found a significant and reproducible reduction in high-frequency AF between EO and EC in the bilateral PSMC and the supplementary motor area (SMA), and an increase in high-frequency AF in the left middle occipital gyrus (MOG). Furthermore, we investigated the effect of sampling rate by down-sampling the data to effective TR = 2 s. Briefly, by using the rapid sampling rate, we were able to detect more regions with significant differences while identifying fewer artifactual differences in the high-frequency bands as compared to the down-sampled dataset. We concluded that (1) high-frequency fluctuations of rs-fMRI signals can be modulated by different resting states and thus may be of physiological importance; and (2) the regression of covariates and the use of fast sampling rates are superior for revealing high-frequency differences in rs-fMRI signals.
Collapse
Affiliation(s)
- Bin-Ke Yuan
- Hangzhou Institute of Service Engineering, Hangzhou Normal University Hangzhou, China ; Center for Cognition and Brain Disorders, Hangzhou Normal University Hangzhou, China ; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University Hangzhou, China
| | - Jue Wang
- Center for Cognition and Brain Disorders, Hangzhou Normal University Hangzhou, China ; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University Hangzhou, China
| | - Yu-Feng Zang
- Center for Cognition and Brain Disorders, Hangzhou Normal University Hangzhou, China ; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University Hangzhou, China
| | - Dong-Qiang Liu
- Center for Cognition and Brain Disorders, Hangzhou Normal University Hangzhou, China ; Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou Normal University Hangzhou, China
| |
Collapse
|
279
|
Brain network informed subject community detection in early-onset schizophrenia. Sci Rep 2014; 4:5549. [PMID: 24989351 PMCID: PMC4929688 DOI: 10.1038/srep05549] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 06/11/2014] [Indexed: 11/08/2022] Open
Abstract
Early-onset schizophrenia (EOS) offers a unique opportunity to study pathophysiological mechanisms and development of schizophrenia. Using 26 drug-naïve, first-episode EOS patients and 25 age- and gender-matched control subjects, we examined intrinsic connectivity network (ICN) deficits underlying EOS. Due to the emerging inconsistency between behavior-based psychiatric disease classification system and the underlying brain dysfunctions, we applied a fully data-driven approach to investigate whether the subjects can be grouped into highly homogeneous communities according to the characteristics of their ICNs. The resultant subject communities and the representative characteristics of ICNs were then associated with the clinical diagnosis and multivariate symptom patterns. A default mode ICN was statistically absent in EOS patients. Another frontotemporal ICN further distinguished EOS patients with predominantly negative symptoms. Connectivity patterns of this second network for the EOS patients with predominantly positive symptom were highly similar to typically developing controls. Our post-hoc functional connectivity modeling confirmed that connectivity strength in this frontotemporal circuit was significantly modulated by relative severity of positive and negative syndromes in EOS. This study presents a novel subtype discovery approach based on brain networks and proposes complex links between brain networks and symptom patterns in EOS.
Collapse
|
280
|
Toward neurobiological characterization of functional homogeneity in the human cortex: regional variation, morphological association and functional covariance network organization. Brain Struct Funct 2014; 220:2485-507. [DOI: 10.1007/s00429-014-0795-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 05/11/2014] [Indexed: 01/14/2023]
|
281
|
Zuo XN, Xing XX. Test-retest reliabilities of resting-state FMRI measurements in human brain functional connectomics: a systems neuroscience perspective. Neurosci Biobehav Rev 2014; 45:100-18. [PMID: 24875392 DOI: 10.1016/j.neubiorev.2014.05.009] [Citation(s) in RCA: 467] [Impact Index Per Article: 46.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 05/12/2014] [Accepted: 05/15/2014] [Indexed: 12/20/2022]
Abstract
Resting-state functional magnetic resonance imaging (RFMRI) enables researchers to monitor fluctuations in the spontaneous brain activities of thousands of regions in the human brain simultaneously, representing a popular tool for macro-scale functional connectomics to characterize normal brain function, mind-brain associations, and the various disorders. However, the test-retest reliability of RFMRI remains largely unknown. We review previously published papers on the test-retest reliability of voxel-wise metrics and conduct a meta-summary reliability analysis of seven common brain networks. This analysis revealed that the heteromodal associative (default, control, and attention) networks were mostly reliable across the seven networks. Regarding examined metrics, independent component analysis with dual regression, local functional homogeneity and functional homotopic connectivity were the three mostly reliable RFMRI metrics. These observations can guide the use of reliable metrics and further improvement of test-retest reliability for other metics in functional connectomics. We discuss the main issues with low reliability related to sub-optimal design and the choice of data processing options. Future research should use large-sample test-retest data to rectify both the within-subject and between-subject variability of RFMRI measurements and accelerate the application of functional connectomics.
Collapse
Affiliation(s)
- Xi-Nian Zuo
- Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Laboratory for Functional Connectome and Development, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Magnetic Resonance Imaging Research Center, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Xiu-Xia Xing
- College of Applied Sciences, Beijing University of Technology, Beijing 100124, China.
| |
Collapse
|
282
|
Kucukboyaci NE, Kemmotsu N, Cheng CE, Girard HM, Tecoma ES, Iragui VJ, McDonald CR. Functional connectivity of the hippocampus in temporal lobe epilepsy: feasibility of a task-regressed seed-based approach. Brain Connect 2014; 3:464-74. [PMID: 23869604 DOI: 10.1089/brain.2013.0150] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE Resting-state functional connectivity (FC) has revealed marked network dysfunction in patients with temporal lobe epilepsy (TLE) compared to healthy controls. However, the nature and the location of these changes have not been fully elucidated nor confirmed by other methodologies. We assessed the presence of hippocampal FC changes in TLE based on the low frequency residuals of task-related functional magnetic resonance imaging data after the removal of task-related activation [i.e., task-regressed functional connectivity MRI (fcMRI)]. METHOD We employed a novel, task-regressed approach to quantify hippocampal FC, and compare hippocampal FC in 17 patients with unilateral TLE (9 left) with 17 healthy controls. RESULTS Our results suggest widespread FC reductions in the mesial cortex associated with the default mode network (DMN), and some local FC increases in the lateral portions of the right hemisphere. We found more pronounced FC decreases in the left hemisphere than in the right, and these FC decreases were greatest in patients with left TLE. Moreover, the FC reductions observed between the hippocampus and posterior cingulate, inferior parietal, paracentral regions are in agreement with previous resting state studies. CONCLUSIONS Consistent with the existing literature, FC reductions in TLE appear widespread with prominent reductions in the medial portion of the DMN. Our data expand the literature by demonstrating that reductions in FC may be greatest in the left hemisphere and in patients with left TLE. Overall, our findings suggest that task-regressed FC is a viable alternative to resting state and that future studies may extract similar information on network connectivity from already existing datasets.
Collapse
|
283
|
Schaefer A, Margulies DS, Lohmann G, Gorgolewski KJ, Smallwood J, Kiebel SJ, Villringer A. Dynamic network participation of functional connectivity hubs assessed by resting-state fMRI. Front Hum Neurosci 2014; 8:195. [PMID: 24860458 PMCID: PMC4018560 DOI: 10.3389/fnhum.2014.00195] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 03/18/2014] [Indexed: 12/13/2022] Open
Abstract
Network studies of large-scale brain connectivity have demonstrated that highly connected areas, or “hubs,” are a key feature of human functional and structural brain organization. We use resting-state functional MRI data and connectivity clustering to identify multi-network hubs and show that while hubs can belong to multiple networks their degree of integration into these different networks varies dynamically over time. The extent of the network variation was related to the connectedness of the hub. In addition, we found that these network dynamics were inversely related to positive self-generated thoughts reported by individuals and were further decreased with older age. Moreover, the left caudate varied its degree of participation between a default mode subnetwork and a limbic network. This variation was predictive of individual differences in the reports of past-related thoughts. These results support an association between ongoing thought processes and network dynamics and offer a new approach to investigate the brain dynamics underlying mental experience.
Collapse
Affiliation(s)
- Alexander Schaefer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Daniel S Margulies
- Max Planck Research Group for Neuroanatomy & Connectivity, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | - Gabriele Lohmann
- Department of High-field Magnetic Resonance, Max Planck Institute for Biological Cybernetics Tübingen, Germany
| | - Krzysztof J Gorgolewski
- Max Planck Research Group for Neuroanatomy & Connectivity, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany
| | | | - Stefan J Kiebel
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Department of Neurology, Biomagnetic Center, University Clinics Jena Jena, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences Leipzig, Germany ; Berlin School of Mind and Brain, Mind and Brain Institute Berlin, Germany ; Department of Cognitive Neurology, University Hospital Leipzig Leipzig, Germany ; Center for Stroke Research, Charité - Universitätsmedizin Berlin, Germany
| |
Collapse
|
284
|
Wei GX, Dong HM, Yang Z, Luo J, Zuo XN. Tai Chi Chuan optimizes the functional organization of the intrinsic human brain architecture in older adults. Front Aging Neurosci 2014; 6:74. [PMID: 24860494 PMCID: PMC4029006 DOI: 10.3389/fnagi.2014.00074] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/02/2014] [Indexed: 11/24/2022] Open
Abstract
Whether Tai Chi Chuan (TCC) can influence the intrinsic functional architecture of the human brain remains unclear. To examine TCC-associated changes in functional connectomes, resting-state functional magnetic resonance images were acquired from 40 older individuals including 22 experienced TCC practitioners (experts) and 18 demographically matched TCC-naïve healthy controls, and their local functional homogeneities across the cortical mantle were compared. Compared to the controls, the TCC experts had significantly greater and more experience-dependent functional homogeneity in the right post-central gyrus (PosCG) and less functional homogeneity in the left anterior cingulate cortex (ACC) and the right dorsal lateral prefrontal cortex. Increased functional homogeneity in the PosCG was correlated with TCC experience. Intriguingly, decreases in functional homogeneity (improved functional specialization) in the left ACC and increases in functional homogeneity (improved functional integration) in the right PosCG both predicted performance gains on attention network behavior tests. These findings provide evidence for the functional plasticity of the brain’s intrinsic architecture toward optimizing locally functional organization, with great implications for understanding the effects of TCC on cognition, behavior and health in aging population.
Collapse
Affiliation(s)
- Gao-Xia Wei
- Key Laboratory of Behavioral Science, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Key Laboratory of Mental Health, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Laboratory for Functional Connectome and Development, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Magnetic Resonance Imaging Research Center, Institute of Psychology - Chinese Academy of Sciences Beijing, China
| | - Hao-Ming Dong
- Key Laboratory of Behavioral Science, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Laboratory for Functional Connectome and Development, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; University of Chinese Academy of Sciences Beijing, China
| | - Zhi Yang
- Key Laboratory of Behavioral Science, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Laboratory for Functional Connectome and Development, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Magnetic Resonance Imaging Research Center, Institute of Psychology - Chinese Academy of Sciences Beijing, China
| | - Jing Luo
- Key Laboratory of Mental Health, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Beijing Key Laboratory of Learning and Cognition, Department of Psychology, Capital Normal University Beijing, China
| | - Xi-Nian Zuo
- Key Laboratory of Behavioral Science, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Laboratory for Functional Connectome and Development, Institute of Psychology - Chinese Academy of Sciences Beijing, China ; Magnetic Resonance Imaging Research Center, Institute of Psychology - Chinese Academy of Sciences Beijing, China
| |
Collapse
|
285
|
Dosage effects of BDNF Val66Met polymorphism on cortical surface area and functional connectivity. J Neurosci 2014; 34:2645-51. [PMID: 24523553 DOI: 10.1523/jneurosci.3501-13.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The single nucleotide polymorphism (SNP) that leads to a valine-to-methionine substitution at codon 66 (Val66Met) in BDNF is correlated with differences in cognitive and memory functions, as well as with several neurological and psychiatric disorders. MRI studies have already shown that this genetic variant contributes to changes in cortical thickness and volume, but whether the Val66Met polymorphism affects the cortical surface area of healthy subjects remains unclear. Here, we used multimodal MRI to study whether this polymorphism would affect the cortical morphology and resting-state functional connectivity of a large sample of healthy Han Chinese human subjects. An SNP-wise general linear model analysis revealed a "dosage effect" of the Met allele, specifically a stepwise increase in cortical surface area of the right anterior insular cortex with increasing numbers of the Met allele. Moreover, we found enhanced functional connectivity between the anterior insular and the dorsolateral prefrontal cortices that was linked with the dosage of the Met allele. In conclusion, these data demonstrated a "dosage effect" of BDNF Val66Met on normal cortical structure and function, suggesting a new path for exploring the mechanisms underlying the effects of genotype on cognition.
Collapse
|
286
|
Abstract
Although brain plasticity is greatest in the first few years of life, the brain continues to be shaped by experience throughout adulthood. Advances in fMRI have enabled us to examine the plasticity of large-scale networks using blood oxygen level–dependent (BOLD) correlations measured at rest. Resting-state functional connectivity analysis makes it possible to measure task-independent changes in brain function and therefore could provide unique insights into experience-dependent brain plasticity in humans. Here, we evaluate the hypothesis that resting-state functional connectivity reflects the repeated history of co-activation between brain regions. To this end, we review resting-state fMRI studies in the sensory, motor, and cognitive learning literature. This body of research provides evidence that the brain’s resting-state functional architecture displays dynamic properties in young adulthood.
Collapse
Affiliation(s)
| | - Allyson P. Mackey
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Silvia A. Bunge
- Department of Psychology, University of California, Berkeley, Berkeley, CA, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
| |
Collapse
|
287
|
Jin SH, Jeong W, Lee DS, Jeon BS, Chung CK. Preserved high-centrality hubs but efficient network reorganization during eyes-open state compared with eyes-closed resting state: an MEG study. J Neurophysiol 2014; 111:1455-65. [PMID: 24431400 DOI: 10.1152/jn.00585.2013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A question to be addressed in the present study is how different the eyes-closed (EC) and eyes-open (EO) resting states are across frequency bands in terms of efficiency and centrality of the brain functional network. We investigated both the global and nodal efficiency and betweenness centrality in the EC and EO resting states from 39 volunteers. Mutual information was used to obtain the functional connectivity for each of the four frequency bands (theta, alpha, beta, and gamma). We showed that the cortical hubs with high betweenness centrality were maintained in the EC and EO resting states. We further showed that these hubs were associated with more than three frequency bands, suggesting that these hubs play an important role in the brain functional network at multiple temporal scales in the resting states. Enhanced global efficiency values were found in the theta and alpha bands in the EO state compared with those in the EC state. Moreover, it turned out that in the EO state the functional network was reorganized to enhance nodal efficiency at the nodes related to both the default mode and the dorsal attention networks and sensory-related resting-state networks. This result suggests that in the EO state the brain functional network was efficiently reorganized, facilitating the adaptation of the brain network to the change in state, which could help in understanding brain disorders that have a disturbance in communication with external environments by using the adaptation ability of brain functional networks.
Collapse
Affiliation(s)
- Seung-Hyun Jin
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea
| | | | | | | | | |
Collapse
|
288
|
Raemaekers M, Schellekens W, van Wezel RJA, Petridou N, Kristo G, Ramsey NF. Patterns of resting state connectivity in human primary visual cortical areas: a 7T fMRI study. Neuroimage 2013; 84:911-21. [PMID: 24099850 DOI: 10.1016/j.neuroimage.2013.09.060] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 12/20/2022] Open
Abstract
The nature and origin of fMRI resting state fluctuations and connectivity are still not fully known. More detailed knowledge on the relationship between resting state patterns and brain function may help to elucidate this matter. We therefore performed an in depth study of how resting state fluctuations map to the well known architecture of the visual system. We investigated resting state connectivity at both a fine and large scale within and across visual areas V1, V2 and V3 in ten human subjects using a 7Tesla scanner. We found evidence for several coexisting and overlapping connectivity structures at different spatial scales. At the fine-scale level we found enhanced connectivity between the same topographic locations in the fieldmaps of V1, V2 and V3, enhanced connectivity to the contralateral functional homologue, and to a lesser extent enhanced connectivity between iso-eccentric locations within the same visual area. However, by far the largest proportion of the resting state fluctuations occurred within large-scale bilateral networks. These large-scale networks mapped to some extent onto the architecture of the visual system and could thereby obscure fine-scale connectivity. In fact, most of the fine-scale connectivity only became apparent after the large-scale network fluctuations were filtered from the timeseries. We conclude that fMRI resting state fluctuations in the visual cortex may in fact be a composite signal of different overlapping sources. Isolating the different sources could enhance correlations between BOLD and electrophysiological correlates of resting state activity.
Collapse
Affiliation(s)
- Mathijs Raemaekers
- Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
| | | | | | | | | | | |
Collapse
|
289
|
Wang X, Jiao Y, Tang T, Wang H, Lu Z. Investigating univariate temporal patterns for intrinsic connectivity networks based on complexity and low-frequency oscillation: a test-retest reliability study. Neuroscience 2013; 254:404-26. [PMID: 24042040 DOI: 10.1016/j.neuroscience.2013.09.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 08/18/2013] [Accepted: 09/04/2013] [Indexed: 11/25/2022]
Abstract
Intrinsic connectivity networks (ICNs) are composed of spatial components and time courses. The spatial components of ICNs were discovered with moderate-to-high reliability. So far as we know, few studies focused on the reliability of the temporal patterns for ICNs based their individual time courses. The goals of this study were twofold: to investigate the test-retest reliability of temporal patterns for ICNs, and to analyze these informative univariate metrics. Additionally, a correlation analysis was performed to enhance interpretability. Our study included three datasets: (a) short- and long-term scans, (b) multi-band echo-planar imaging (mEPI), and (c) eyes open or closed. Using dual regression, we obtained the time courses of ICNs for each subject. To produce temporal patterns for ICNs, we applied two categories of univariate metrics: network-wise complexity and network-wise low-frequency oscillation. Furthermore, we validated the test-retest reliability for each metric. The network-wise temporal patterns for most ICNs (especially for default mode network, DMN) exhibited moderate-to-high reliability and reproducibility under different scan conditions. Network-wise complexity for DMN exhibited fair reliability (ICC<0.5) based on eyes-closed sessions. Specially, our results supported that mEPI could be a useful method with high reliability and reproducibility. In addition, these temporal patterns were with physiological meanings, and certain temporal patterns were correlated to the node strength of the corresponding ICN. Overall, network-wise temporal patterns of ICNs were reliable and informative and could be complementary to spatial patterns of ICNs for further study.
Collapse
Affiliation(s)
- X Wang
- School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China; Key Laboratory of Child Development and Learning Science (Ministry of Education), Southeast University, Nanjing 210096, China
| | | | | | | | | |
Collapse
|
290
|
Molloy EK, Meyerand ME, Birn RM. The influence of spatial resolution and smoothing on the detectability of resting-state and task fMRI. Neuroimage 2013; 86:221-30. [PMID: 24021836 DOI: 10.1016/j.neuroimage.2013.09.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 08/30/2013] [Accepted: 09/01/2013] [Indexed: 10/26/2022] Open
Abstract
Functional MRI blood oxygen level-dependent (BOLD) signal changes can be subtle, motivating the use of imaging parameters and processing strategies that maximize the temporal signal-to-noise ratio (tSNR) and thus the detection power of neuronal activity-induced fluctuations. Previous studies have shown that acquiring data at higher spatial resolutions results in greater percent BOLD signal changes, and furthermore that spatially smoothing higher resolution fMRI data improves tSNR beyond that of data originally acquired at a lower resolution. However, higher resolution images come at the cost of increased acquisition time, and the number of image volumes also influences detectability. The goal of our study is to determine how the detection power of neuronally induced BOLD fluctuations acquired at higher spatial resolutions and then spatially smoothed compares to data acquired at the lower resolutions with the same imaging duration. The number of time points acquired during a given amount of imaging time is a practical consideration given the limited ability of certain populations to lie still in the MRI scanner. We compare acquisitions at three different in-plane spatial resolutions (3.50×3.50mm(2), 2.33×2.33mm(2), 1.75×1.75mm(2)) in terms of their tSNR, contrast-to-noise ratio, and the power to detect both task-related activation and resting-state functional connectivity. The impact of SENSE acceleration, which speeds up acquisition time increasing the number of images collected, is also evaluated. Our results show that after spatially smoothing the data to the same intrinsic resolution, lower resolution acquisitions have a slightly higher detection power of task-activation in some, but not all, brain areas. There were no significant differences in functional connectivity as a function of resolution after smoothing. Similarly, the reduced tSNR of fMRI data acquired with a SENSE factor of 2 is offset by the greater number of images acquired, resulting in few significant differences in detection power of either functional activation or connectivity after spatial smoothing.
Collapse
Affiliation(s)
- Erin K Molloy
- Department of Psychiatry, University of Wisconsin Madison, Madison, WI, USA
| | - Mary E Meyerand
- Department of Biomedical Engineering, University of Wisconsin Madison, Madison, WI, USA; Department of Medical Physics, University of Wisconsin Madison, Madison, WI, USA
| | - Rasmus M Birn
- Department of Psychiatry, University of Wisconsin Madison, Madison, WI, USA; Department of Medical Physics, University of Wisconsin Madison, Madison, WI, USA.
| |
Collapse
|
291
|
Jung WH, Kang DH, Kim E, Shin KS, Jang JH, Kwon JS. Abnormal corticostriatal-limbic functional connectivity in obsessive-compulsive disorder during reward processing and resting-state. NEUROIMAGE-CLINICAL 2013; 3:27-38. [PMID: 24179846 PMCID: PMC3791288 DOI: 10.1016/j.nicl.2013.06.013] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 11/16/2022]
Abstract
Compulsive behaviors in obsessive–compulsive disorder (OCD) may be related to deficits in reward processing mediated by corticostriatal circuitry, a brain network implicated in the pathophysiology of OCD. Performing compulsive actions can be perceived as a reward to OCD patients because it temporarily reduces the anxiety provoked by obsessions. Although most OCD literature provides evidence of altered regional activity in these corticostriatal circuits, very little is known about the connectivity between individual regions of the corticostriatal-limbic circuits, including the cognitive and affective neural circuitry associated with OCD. Thus, this study investigated the differences in functional connectivity (FC) patterns in this network during resting-state and incentive processing. Nineteen patients with OCD and 18 well-matched healthy controls were scanned during resting-state and a monetary incentive delay task (task state). FC was assessed using both voxel-wise and region-of-interest (ROI)-wise analyses. Voxel-wise FC analysis with the nucleus accumbens seed revealed that patients with OCD exhibited increased FC between the nucleus accumbens and the lateral orbitofrontal cortex during resting-state. Additionally, these patients showed decreased FC between the nucleus accumbens and limbic areas such as the amygdala during incentive processing. Exploratory ROI-wise FC analysis revealed that OCD patients demonstrated enhanced FC between the nucleus accumbens and the lateral orbitofrontal cortex and increased total connectivity of the lateral orbitofrontal cortex during resting-state. Additionally, patients showed alterations in FC between resting and task state. This study provides evidence that patients with OCD have altered FC in the corticostriatal-limbic network, particularly in striatal-amygdala and striatal-orbitofrontal circuitry, during incentive processing and resting-state. These findings also emphasize that functional connections in the network are modulated by affective/motivational states and further suggest that OCD patients may have abnormalities of such modulation in this network. Corticostriatal-limbic FC analysis of task-based and resting-state fMRI data in OCD Dysfunctional connectivity in striatal–amygdala during reward task in OCD Dysfunctional connectivity in striatal–orbitofrontal cortex at rest in OCD FC levels in corticostriatal-limbic network are modulated by affective state. OCD patients have deficits in this modulation of the corticostriatal-limbic network.
Collapse
Affiliation(s)
- Wi Hoon Jung
- Institute of Human Behavioral Medicine, SNU-MRC, Seoul, South Korea
| | | | | | | | | | | |
Collapse
|
292
|
Birn RM, Molloy EK, Patriat R, Parker T, Meier TB, Kirk GR, Nair VA, Meyerand ME, Prabhakaran V. The effect of scan length on the reliability of resting-state fMRI connectivity estimates. Neuroimage 2013; 83:550-8. [PMID: 23747458 DOI: 10.1016/j.neuroimage.2013.05.099] [Citation(s) in RCA: 551] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 04/26/2013] [Accepted: 05/23/2013] [Indexed: 01/13/2023] Open
Abstract
There has been an increasing use of functional magnetic resonance imaging (fMRI) by the neuroscience community to examine differences in functional connectivity between normal control groups and populations of interest. Understanding the reliability of these functional connections is essential to the study of neurological development and degenerate neuropathological conditions. To date, most research assessing the reliability with which resting-state functional connectivity characterizes the brain's functional networks has been on scans between 3 and 11 min in length. In our present study, we examine the test-retest reliability and similarity of resting-state functional connectivity for scans ranging in length from 3 to 27 min as well as for time series acquired during the same length of time but excluding half the time points via sampling every second image. Our results show that reliability and similarity can be greatly improved by increasing the scan lengths from 5 min up to 13 min, and that both the increase in the number of volumes as well as the increase in the length of time over which these volumes was acquired drove this increase in reliability. This improvement in reliability due to scan length is much greater for scans acquired during the same session. Gains in intersession reliability began to diminish after 9-12 min, while improvements in intrasession reliability plateaued around 12-16 min. Consequently, new techniques that improve reliability across sessions will be important for the interpretation of longitudinal fMRI studies.
Collapse
Affiliation(s)
- Rasmus M Birn
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, USA; Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA; Neurosciences Training Program, University of Wisconsin-Madison, Madison, WI, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|