Increasing fMRI sampling rate improves Granger causality estimates

Tutkimustuotos: Lehtiartikkeli

Tutkijat

Organisaatiot

  • Massachusetts General Hospital
  • National Yang-Ming University
  • National Taiwan University

Kuvaus

Estimation of causal interactions between brain areas is necessary for elucidating large-scale functional brain networks underlying behavior and cognition. Granger causality analysis of time series data can quantitatively estimate directional information flow between brain regions. Here, we show that such estimates are significantly improved when the temporal sampling rate of functional magnetic resonance imaging (fMRI) is increased 20-fold. Specifically, healthy volunteers performed a simple visuomotor task during blood oxygenation level dependent (BOLD) contrast based whole-head inverse imaging (InI). Granger causality analysis based on raw InI BOLD data sampled at 100-ms resolution detected the expected causal relations, whereas when the data were downsampled to the temporal resolution of 2 s typically used in echo-planar fMRI, the causality could not be detected. An additional control analysis, in which we SINC interpolated additional data points to the downsampled time series at 0.1-s intervals, confirmed that the improvements achieved with the real InI data were not explainable by the increased time-series length alone. We therefore conclude that the high-temporal resolution of InI improves the Granger causality connectivity analysis of the human brain.

Yksityiskohdat

AlkuperäiskieliEnglanti
Artikkelie100319
Sivut1-13
JulkaisuPloS one
Vuosikerta9
Numero6
TilaJulkaistu - 26 kesäkuuta 2014
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

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