Estimation of FMRI response delays. Neuroimage 2003 Feb;18(2):494-504
Date
02/22/2003Pubmed ID
12595202DOI
10.1016/s1053-8119(02)00024-1Scopus ID
2-s2.0-0037331109 (requires institutional sign-in at Scopus site) 42 CitationsAbstract
We present an efficient algorithm using the Hilbert Transform for estimating the delay of the BOLD response to neuronal stimulation. With minimal additional computations, the algorithm estimates parameters generated in the widely used cross-correlation method and simplifies the interpolation required to estimate the response delay from the cross-correlation function. We examined errors in the Hilbert-based delay estimate associated with the use of DFT on short-duration discrete signals and proposed a method for minimizing these errors. Furthermore, we compared the delay estimates obtained with the Hilbert method to those obtained using the onset of the BOLD response. The Hilbert method resulted in less variance in the delay estimate despite the potential for higher variability in the latter part of the BOLD response. This improved delay estimate was attributed to the reduced sensitivity of the Hilbert method to noise contamination compared to the onset method.
Author List
Saad ZS, DeYoe EA, Ropella KMAuthor
Edgar A. DeYoe PhD Adjunct Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AlgorithmsArtifacts
Brain
Computer Simulation
Flicker Fusion
Fourier Analysis
Humans
Image Processing, Computer-Assisted
Magnetic Resonance Imaging
Mathematical Computing
Neurons
Oxygen Consumption
Sensory Thresholds
Synaptic Transmission
