Filtering induces correlation in fMRI resting state data

被引:74
作者
Davey, Catherine E. [1 ,2 ]
Grayden, David B. [1 ]
Egan, Gary F. [3 ,4 ]
Johnston, Leigh A. [1 ,2 ]
机构
[1] Univ Melbourne, Dept Elect & Elect Engn, NeuroEngn Lab, Melbourne, Vic 3010, Australia
[2] Florey Neurosci Inst, Howard Florey Inst, Melbourne, Vic, Australia
[3] Univ Melbourne, Ctr Neurosci, Melbourne, Vic 3010, Australia
[4] Monash Univ, Clayton, Vic 3800, Australia
关键词
FUNCTIONAL CONNECTIVITY; MOTOR CORTEX; AUTOCORRELATION; FLUCTUATIONS; NOISE; MRI;
D O I
10.1016/j.neuroimage.2012.08.022
中图分类号
Q189 [神经科学];
学科分类号
071006 [神经生物学];
摘要
Correlation-based functional MRI connectivity methods typically impose a temporal sample independence assumption on the data. However, the conventional use of temporal filtering to address the high noise content of fMRI data may introduce sample dependence. Violation of the independence assumption has ramifications for the distribution of sample correlation which, if unaccounted for, may invalidate connectivity results. To enable the use of temporal filtering for noise suppression while maintaining the integrity of connectivity results, we derive the distribution of sample correlation between filtered timeseries as a function of the filter frequency response. Corrected distributions are also derived for statistical inference tests of sample correlation between filtered timeseries, including Fisher's z-transformation and the Student's t-test. Crucially, the proposed corrections are valid for any unknown true correlation and arbitrary filter specifications. Empirical simulations demonstrate the potential for temporal filtering to artificially induce connectivity by introducing sample dependence, and verify the utility of the proposed corrections in mitigating this effect The importance of our corrections is exemplified in a resting state fMRI connectivity analysis: seed-voxel correlation maps generated from filtered data using uncorrected test variates yield an unfeasible number of connections to the left primary motor cortex, suggesting artificially induced connectivity, while maps acquired from filtered data using corrected test variates exhibit bilateral connectivity in the primary motor cortex, in conformance with expected results as seen in the literature. (C) 2012 Elsevier Inc. All rights reserved.
引用
收藏
页码:728 / 740
页数:13
相关论文
共 48 条
[1]
[Anonymous], 2009, GRAPHICAL MODELS APP
[2]
[Anonymous], 2003, Introduction to Nessus
[3]
Atlas SW., 2009, MAGNETIC RESONANCE I
[4]
Spontaneous low-frequency blood oxygenation level-dependent fluctuations and functional connectivity analysis of the 'resting' brain [J].
Auer, Dorothee P. .
MAGNETIC RESONANCE IMAGING, 2008, 26 (07) :1055-1064
[5]
Functional MRI of brain activation induced by scanner acoustic noise [J].
Bandettini, PA ;
Jesmanowicz, A ;
Van Kylen, J ;
Birn, RM ;
Hyde, JS .
MAGNETIC RESONANCE IN MEDICINE, 1998, 39 (03) :410-416
[6]
Evaluation of preprocessing steps to compensate for magnetic field distortions due to body movements in BOLD fMRI [J].
Barry, Robert L. ;
Williams, Joy M. ;
Klassen, L. Martyn ;
Gallivan, Jason P. ;
Culham, Jody C. ;
Menon, Ravi S. .
MAGNETIC RESONANCE IMAGING, 2010, 28 (02) :235-244
[7]
Sources of functional magnetic resonance imaging signal fluctuations in the human brain at rest: a 7 T study [J].
Bianciardi, Marta ;
Fukunaga, Masaki ;
van Gelderen, Peter ;
Horovitz, Silvina G. ;
de Zwart, Jacco A. ;
Shmueli, Karin ;
Duyn, Jeff H. .
MAGNETIC RESONANCE IMAGING, 2009, 27 (08) :1019-1029
[8]
Separating respiratory-variation-related neuronal-activity-related fluctuations in fluctuations from fMRI [J].
Birn, RM ;
Diamond, JB ;
Smith, MA ;
Bandettini, PA .
NEUROIMAGE, 2006, 31 (04) :1536-1548
[9]
FUNCTIONAL CONNECTIVITY IN THE MOTOR CORTEX OF RESTING HUMAN BRAIN USING ECHO-PLANAR MRI [J].
BISWAL, B ;
YETKIN, FZ ;
HAUGHTON, VM ;
HYDE, JS .
MAGNETIC RESONANCE IN MEDICINE, 1995, 34 (04) :537-541
[10]
How good is good enough in path analysis of fMRI data? [J].
Bullmore, ET ;
Horwitz, B ;
Honey, G ;
Brammer, M ;
Williams, S ;
Sharma, T .
NEUROIMAGE, 2000, 11 (04) :289-301