title: The Richness of Task-Evoked Hemodynamic Responses Defines a Pseudohierarchy of Functionally Meaningful Brain Networks.
abstract: Functional magnetic resonance imaging can measure distributed and subtle variations in brain responses associated with task performance. However, it is unclear whether the rich variety of responses observed across the brain is functionally meaningful and consistent across individuals. Here, we used a multivariate clustering approach that grouped brain regions into clusters based on the similarity of their task-evoked temporal responses at the individual level, and then established the spatial consistency of these individual clusters at the group level. We observed a stable pseudohierarchy of task-evoked networks in the context of a delayed sequential motor task, where the fractionation of networks was driven by a gradient of involvement in motor sequence preparation versus execution. In line with theories about higher-level cognitive functioning, this gradient evolved in a rostro-caudal manner in the frontal lobe. In addition, parcellations in the cerebellum and basal ganglia matched with known anatomical territories and fiber pathways with the cerebral cortex. These findings demonstrate that subtle variations in brain responses associated with task performance are systematic enough across subjects to define a pseudohierarchy of task-evoked networks. Such networks capture meaningful functional features of brain organization as shaped by a given cognitive context.
authors.affiliation: Functional Neuroimaging Unit, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, University of Montreal, Montreal, Quebec, Canada Department of Psychiatry, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Orban
authors.affiliation: Functional Neuroimaging Unit, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, University of Montreal, Montreal, Quebec, Canada Department of Psychology, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Julien
authors.initials: J
authors.lastname: Doyon
authors.affiliation: Cognitive Neuroscience Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Petrides
authors.affiliation: Department of Cognitive Neuroscience, Radbout University Nijmegen Medical Center, Nijmegen, The Netherlands Donders Institute for Brain, Cognition and Behavior, Radbout University Nijmegen, Nijmegen, The Netherlands.
authors.forename: Maarten
authors.initials: M
authors.lastname: Mennes
authors.affiliation: Functional Neuroimaging Unit, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, University of Montreal, Montreal, Quebec, Canada Department of Physiology and Biomedical Engineering, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Richard
authors.initials: R
authors.lastname: Hoge
authors.affiliation: Functional Neuroimaging Unit, Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, University of Montreal, Montreal, Quebec, Canada Department of Computer Science and Operations Research, University of Montreal, Montreal, Quebec, Canada.
authors.forename: Pierre
authors.initials: P
authors.lastname: Bellec
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D001931:Brain Mapping; D016000:Cluster Analysis; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008959:Models, Neurological; D009434:Neural Pathways / Q000098:blood supply* / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D011597:Psychomotor Performance / Q000502:physiology; D055815:Young Adult
chemical_list: D010100:Oxygen
keywords: clustering analysis; fMRI; functional connectivity; motor preparation and execution; multiscale task-evoked networks
references.citation: IEEE Trans Med Imaging. 2002 Oct;21(10):1280-91
references.pmid: 12585710
references.citation: Nat Rev Neurosci. 2008 Nov;9(11):856-69
references.pmid: 18843271
references.citation: Brain Res Brain Res Rev. 2000 Mar;31(2-3):236-50
references.pmid: 10719151
references.citation: Nat Rev Neurosci. 2002 Aug;3(8):606-16
references.pmid: 12154362
references.citation: Neuroimage. 2010 Jul 1;51(3):1126-39
references.pmid: 20226257
references.citation: Neuroimage. 2009 May 15;46(1):39-46
references.pmid: 19457380
references.citation: J Comput Assist Tomogr. 1994 Mar-Apr;18(2):192-205
references.pmid: 8126267
references.citation: Neuroimage. 2006 Feb 15;29(4):1231-43
references.pmid: 16246590
references.citation: Exp Brain Res. 1987;66(1):155-66
references.pmid: 3582529
references.citation: J Cogn Neurosci. 2010 Nov;22(11):2663-76
references.pmid: 19925191
references.citation: Hum Brain Mapp. 2011 Jun;32(6):856-71
references.pmid: 20572208
references.citation: Neuron. 2010 Feb 25;65(4):550-62
references.pmid: 20188659
references.citation: Neuroreport. 2004 Oct 25;15(15):2327-31
references.pmid: 15640749
references.citation: Cereb Cortex. 2008 Nov;18(11):2553-9
references.pmid: 18296434
references.citation: Neuroimage. 2013 Oct 15;80:505-14
references.pmid: 23631994
references.citation: Cereb Cortex. 2013 Jan;23(1):223-9
references.pmid: 22298730
references.citation: Neuroimage. 2012 Jul 16;61(4):1129-42
references.pmid: 22440648
references.citation: Neurosci Lett. 1997 May 23;227(3):161-4
references.pmid: 9185675
references.citation: Front Neuroinform. 2012 Apr 03;6:7
references.pmid: 22493575
references.citation: Neuroimage. 2006 Jul 1;31(3):1177-87
references.pmid: 16540347
references.citation: Cereb Cortex. 2010 May;20(5):1187-94
references.pmid: 19729393
references.citation: Hum Brain Mapp. 1997;5(5):329-40
references.pmid: 20408237
references.citation: J Neurosci. 2003 Sep 10;23(23):8432-44
references.pmid: 12968006
references.citation: J Neurosci. 2008 Jul 9;28(28):7143-52
references.pmid: 18614684
references.citation: Proc Natl Acad Sci U S A. 2009 Aug 4;106(31):13040-5
references.pmid: 19620724
references.citation: J Neurophysiol. 2012 Oct;108(8):2242-63
references.pmid: 22832566
references.citation: Neuroreport. 1997 Mar 24;8(5):1257-61
references.pmid: 9175125
references.citation: Trends Neurosci. 1990 Jul;13(7):266-71
references.pmid: 1695401
references.citation: J Neurosci. 1999 Feb 15;19(4):1446-63
references.pmid: 9952421
references.citation: J Neurophysiol. 2011 Nov;106(5):2322-45
references.pmid: 21795627
references.citation: Proc Natl Acad Sci U S A. 2012 Apr 3;109(14):5487-92
references.pmid: 22431587
references.citation: J Neurosci. 2007 Oct 3;27(40):10659-73
references.pmid: 17913900
references.citation: Neuron. 2011 Nov 17;72(4):665-78
references.pmid: 22099467
references.citation: Cereb Cortex. 2010 Apr;20(4):953-65
references.pmid: 19684249
references.citation: Magn Reson Imaging. 2007 Jul;25(6):860-8
references.pmid: 17482412
references.citation: Neuroimage. 2002 Jul;16(3 Pt 1):551-63
references.pmid: 12169242
references.citation: Hum Brain Mapp. 2012 Jul;33(7):1536-52
references.pmid: 21761505
references.citation: J Neurophysiol. 2003 Jul;90(1):360-71
references.pmid: 12660356
references.citation: Trends Cogn Sci. 2013 May;17(5):241-54
references.pmid: 23579055
references.citation: Neuroimage. 2011 Feb 14;54(4):2950-9
references.pmid: 20974260
references.citation: Neuroimage. 2010 Jan 15;49(2):1171-9
references.pmid: 19800409
references.citation: Neuroreport. 2000 Nov 27;11(17):3849-53
references.pmid: 11117502
references.citation: Hum Brain Mapp. 2001 Nov;14(3):140-51
references.pmid: 11559959
references.citation: J Neurophysiol. 2001 May;85(5):1858-63
references.pmid: 11353002
references.citation: Exp Brain Res. 1987;67(3):656-62
references.pmid: 3653323
references.citation: Neuroimage. 2008 Feb 1;39(3):1356-69
references.pmid: 18024158
references.citation: J Neurophysiol. 2011 Sep;106(3):1125-65
references.pmid: 21653723
references.citation: J Neurophysiol. 1991 Sep;66(3):705-18
references.pmid: 1753282
references.citation: Front Neurosci. 2010 Dec 08;4:200
references.pmid: 21151783
references.citation: Nat Rev Neurosci. 2009 Sep;10(9):659-69
references.pmid: 19672274
references.citation: Neuroimage. 2009 Feb 15;44(4):1369-79
references.pmid: 19059350