Automatic search for fMRI connectivity mapping: An alternative to Granger causality testing using formal equivalences among SEM path modeling, VAR, and unified SEM

Kathleen M. Gates, Peter Molenaar, Frank Gerard Hillary, Nilam Ram, Michael J. Rovine

Research output: Contribution to journalArticlepeer-review

92 Scopus citations

Abstract

Modeling the relationships among brain regions of interest (ROIs) carries unique potential to explicate how the brain orchestrates information processing. However, hurdles arise when using functional MRI data. Variation in ROI activity contains sequential dependencies and shared influences on synchronized activation. Consequently, both lagged and contemporaneous relationships must be considered for unbiased statistical parameter estimation. Identifying these relationships using a data-driven approach could guide theory-building regarding integrated processing. The present paper demonstrates how the unified SEM attends to both lagged and contemporaneous influences on ROI activity. Additionally, this paper offers an approach akin to Granger causality testing, Lagrange multiplier testing, for statistically identifying directional influence among ROIs and employs this approach using an automatic search procedure to arrive at the optimal model. Rationale for this equivalence is offered by explicating the formal relationships among path modeling, vector autoregression, and unified SEM. When applied to simulated data, biases in estimates which do not consider both lagged and contemporaneous paths become apparent. Finally, the use of unified SEM with the automatic search procedure is applied to an empirical data example.

Original languageEnglish (US)
Pages (from-to)1118-1125
Number of pages8
JournalNeuroImage
Volume50
Issue number3
DOIs
StatePublished - Apr 15 2010

All Science Journal Classification (ASJC) codes

  • Neurology
  • Cognitive Neuroscience

Fingerprint Dive into the research topics of 'Automatic search for fMRI connectivity mapping: An alternative to Granger causality testing using formal equivalences among SEM path modeling, VAR, and unified SEM'. Together they form a unique fingerprint.

Cite this