title: Extracting intrinsic functional networks with feature-based group independent component analysis.
abstract: There is increasing use of functional imaging data to understand the macro-connectome of the human brain. Of particular interest is the structure and function of intrinsic networks (regions exhibiting temporally coherent activity both at rest and while a task is being performed), which account for a significant portion of the variance in functional MRI data. While networks are typically estimated based on the temporal similarity between regions (based on temporal correlation, clustering methods, or independent component analysis [ICA]), some recent work has suggested that these intrinsic networks can be extracted from the inter-subject covariation among highly distilled features, such as amplitude maps reflecting regions modulated by a task or even coordinates extracted from large meta analytic studies. In this paper our goal was to explicitly compare the networks obtained from a first-level ICA (ICA on the spatio-temporal functional magnetic resonance imaging (fMRI) data) to those from a second-level ICA (i.e., ICA on computed features rather than on the first-level fMRI data). Convergent results from simulations, task-fMRI data, and rest-fMRI data show that the second-level analysis is slightly noisier than the first-level analysis but yields strikingly similar patterns of intrinsic networks (spatial correlations as high as 0.85 for task data and 0.65 for rest data, well above the empirical null) and also preserves the relationship of these networks with other variables such as age (for example, default mode network regions tended to show decreased low frequency power for first-level analyses and decreased loading parameters for second-level analyses). In addition, the best-estimated second-level results are those which are the most strongly reflected in the input feature. In summary, the use of feature-based ICA appears to be a valid tool for extracting intrinsic networks. We believe it will become a useful and important approach in the study of the macro-connectome, particularly in the context of data fusion.
authors.affiliation: The Mind Research Network, 1101 Yale Blvd NE, Albuquerque, NM, 87106, USA, vcalhoun@unm.edu.
authors.forename: Vince D
authors.initials: VD
authors.lastname: Calhoun
authors.forename: Elena
authors.initials: E
authors.lastname: Allen
mesh_terms: D000328:Adult; D003198:Computer Simulation; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000502:physiology*; D013223:Statistics as Topic / Q000379:methods*; D055815:Young Adult
references.citation: Hum Brain Mapp. 2009 Mar;30(3):711-24
references.pmid: 18266214
references.citation: Hum Brain Mapp. 2007 Nov;28(11):1251-66
references.pmid: 17274023
references.citation: Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4734-9
references.pmid: 20176931
references.citation: Hum Brain Mapp. 2010 Aug;31(8):1207-16
references.pmid: 20063361
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 4;106(31):13040-5
references.pmid: 19620724
references.citation: Neuroimage. 1995 Jun;2(2):157-65
references.pmid: 9343598
references.citation: Brain Connect. 2011 Jun 8;1(2):1-19
references.pmid: 21808745
references.citation: Hum Brain Mapp. 2009 Dec;30(12):3865-86
references.pmid: 19507160
references.citation: IEEE Trans Inf Technol Biomed. 2009 Sep;13(5):711-20
references.pmid: 19273016
references.citation: Neuroimage. 2009 Mar;45(1 Suppl):S163-72
references.pmid: 19059344
references.citation: Neuroimage. 2003 Nov;20(3):1661-9
references.pmid: 14642476
references.citation: Hum Brain Mapp. 2001 Nov;14(3):140-51
references.pmid: 11559959
references.citation: Front Neuroinform. 2011 Dec 23;5:33
references.pmid: 22275896
references.citation: Cereb Cortex. 2009 Oct;19(10):2209-29
references.pmid: 19221144
references.citation: Science. 2002 Sep 6;297(5587):1706-8
references.pmid: 12215648
references.citation: Hum Brain Mapp. 2006 Jul;27(7):598-610
references.pmid: 16342150
references.citation: J Cogn Neurosci. 2011 Dec;23(12):4022-37
references.pmid: 21671731
references.citation: Neuron. 2010 Feb 25;65(4):550-62
references.pmid: 20188659
references.citation: Brain Connect. 2011;1(2):133-45
references.pmid: 22180852
references.citation: Neuroimage. 2004 Jul;22(3):1214-22
references.pmid: 15219593
references.citation: Vis Neurosci. 2011 May;28(3):247-61
references.pmid: 21554775
references.citation: Front Neuroinform. 2010 Apr 21;3:36
references.pmid: 20461147
references.citation: J Neurosci Methods. 2012 Feb 15;204(1):68-81
references.pmid: 22108139
references.citation: Neural Comput. 1995 Nov;7(6):1129-59
references.pmid: 7584893
references.citation: J Neurosci Methods. 2008 Jul 15;172(1):137-41
references.pmid: 18501969
references.citation: Hum Brain Mapp. 2011 Dec;32(12):2075-95
references.pmid: 21162045
references.citation: Cereb Cortex. 2008 Aug;18(8):1856-64
references.pmid: 18063564
references.citation: Front Syst Neurosci. 2011 Feb 04;5:2
references.pmid: 21442040
references.citation: Hum Brain Mapp. 1998;6(3):160-88
references.pmid: 9673671
references.citation: Neuroimage. 2010 May 15;51(1):288-99
references.pmid: 20153834
references.citation: Neuroimage. 2012 Feb 15;59(4):4160-7
references.pmid: 22178299
references.citation: Prog Neuropsychopharmacol Biol Psychiatry. 2011 Mar 30;35(2):473-82
references.pmid: 21185903
references.citation: Neuroimage. 2010 Aug 1;52(1):379-88
references.pmid: 20350608
references.citation: Hum Brain Mapp. 2009 Sep;30(9):2953-70
references.pmid: 19172631
references.citation: Neuroimage. 2002 Jul;16(3 Pt 1):551-63
references.pmid: 12169242
references.citation: Hum Brain Mapp. 2008 Jul;29(7):828-38
references.pmid: 18438867
references.citation: J Neurophysiol. 2010 Jan;103(1):297-321
references.pmid: 19889849
references.citation: Neuroimage. 2005 Mar;25(1):294-311
references.pmid: 15734364
references.citation: Hum Brain Mapp. 2009 Jul;30(7):2293-303
references.pmid: 19206103
references.citation: Neuroimage. 2010 Feb 1;49(3):2626-37
references.pmid: 19733247