Robust estimation of the hemodynamic response function in asynchronous multitasks multisessions event-related fMRI paradigms
نویسندگان
چکیده
منابع مشابه
Evaluation of Hemodynamic Response Function in Vision and Motor Brain Regions for the Young and Elderly Adults
Introduction: Prior studies comparing Hemodynamic Response Function (HRF) in the young and elderly adults based on fMRI data have reported inconsistent findings for brain vision and motor regions in healthy aging. It is shown that the averaging method employed in all previous works has caused this inconsistency. The averaging is so sensitive to outliers and noise. However, fMRI data are o...
متن کاملCharacterizing the hemodynamic response: effects of presentation rate, sampling procedure, and the possibility of ordering brain activity based on relative timing.
Rapid-presentation event-related functional MRI (ER-fMRI) allows neuroimaging methods based on hemodynamics to employ behavioral task paradigms typical of cognitive settings. However, the sluggishness of the hemodynamic response and its variance provide constraints on how ER-fMRI can be applied. In a series of two studies, estimates of the hemodynamic response in or near the primary visual and ...
متن کاملRobust Bayesian estimation of the hemodynamic response function in event-related BOLD fMRI using basic physiological information.
In BOLD fMRI data analysis, robust and accurate estimation of the Hemodynamic Response Function (HRF) is still under investigation. Parametric methods assume the shape of the HRF to be known and constant throughout the brain, whereas non-parametric methods mostly rely on artificially increasing the signal-to-noise ratio. We extend and develop a previously proposed method that makes use of basic...
متن کاملRapid self-paced event-related functional MRI: feasibility and implications of stimulus- versus response-locked timing.
Many cognitive paradigms require self-paced responses or examine events that occur at unpredictable times. To explore whether functional MRI (fMRI) can accommodate such paradigms, a method allowing rapid, unpredictable trial pacing was developed and tested on 17 subjects using activation of the motor network as a model. Trial onset was determined solely by the subjects' self-paced responses and...
متن کاملDetection versus estimation in event-related fMRI: choosing the optimal stimulus timing.
With the advent of event-related paradigms in functional MRI, there has been interest in finding the optimal stimulus timing, especially when the interstimulus interval is varied during the imaging run. Previous works have proposed stimulus timings to optimize either the estimation of the impulse response function (IRF) or the detection of signal changes. The purpose of this paper is to clarify...
متن کامل