Assessing and compensating for zero-lag correlation effects in time-lagged granger causality analysis of fMRI

Gopikrishna Deshpande, K. Sathian, Xiaoping Hu

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

Effective connectivity in brain networks can be studied using Granger causality analysis, which is based on temporal precedence, while functional connectivity is usually derived using zero-lag correlation. Due to the smoothing of the neuronal activity by the hemodynamic response inherent in the functional magnetic resonance imaging (fMRI) acquisition process, Granger causality, as normally computed from fMRI data, may be contaminated by zero-lag correlation. Simulations performed in this paper showed that the zero-lag correlation does leak into estimates of time-lagged causality. To eliminate this leak, we introduce a method in which the zero-lag influences are explicitly modeled in the vector autoregressive model but omitted while calculating Granger causality. The effectiveness of this method is demonstrated using fMRI data obtained from healthy humans performing a verbal working memory task.

Original languageEnglish (US)
Article number5464489
Pages (from-to)1446-1456
Number of pages11
JournalIEEE Transactions on Biomedical Engineering
Volume57
Issue number6
DOIs
StatePublished - Jun 2010

All Science Journal Classification (ASJC) codes

  • Biomedical Engineering

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