Hemodynamic responses, in general, and the blood oxygenation level-dependent (BOLD) fMRI signal, in particular, provide an indirect measure of neuronal activity. There is strong evidence that the BOLD response correlates well with post-synaptic changes, induced by changes in the excitatory and inhibitory (E-I) balance between active neuronal populations. Typical BOLD responses exhibit transient...

Work on animals indicates that BOLD is preferentially sensitive to local field potentials, and that it correlates most strongly with gamma band neuronal synchronization. Here we investigate how the BOLD signal in humans performing a cognitive task is related to neuronal synchronization across different frequency bands. We simultaneously recorded EEG and BOLD while subjects engaged in a visual a...

Large-vessel BOLD contamination is a serious impediment to localization of neural activity in high-resolution fMRI studies. A new method is presented which estimates and removes the fraction of BOLD signal that arises from oriented vessels, such as cerebral and pial veins in a voxel, by measuring their influence on the phase angle of the complex valued fMRI time series. A maximum likelihood est...

Introduction: Recent studies have shown that regional myocardial oxygenation changes due to coronary artery stenosis may be detected with 2D steady-state free precession (SSFP) blood-oxygen level-dependent (BOLD) imaging [1]. One potential limitation of the 2D SSFP BOLD approach is the disruption of steady-state myocardial signal due to through-plane cardiac motion in the presence of slice-sele...

BOLD imaging is a useful and promising examination tool for mapping human brain functions, using the local alteration of blood oxygenation in the brain caused by neural activity. However, due to the weak signal response, optimisation of the entire methodology is important in BOLD imaging. To enable optimisation of various examination parameters, a fixed BOLD signal is often desirable. The phant...

Calibrated blood oxygenation level dependent (BOLD) imaging, a technique used to measure changes in cerebral O(2) metabolism, depends on an accurate model of how the BOLD signal is affected by the mismatch between changes in cerebral blood flow (CBF) and cerebral metabolic rate of O(2) (CMRO(2)). However, other factors such as the cerebral blood volume (CBV) distribution at rest and with activa...

The blood oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) signal is a widely-accepted marker of brain activity. The acquisition parameters (APs) of fMRI aim at maximizing the signals related to neuronal activity while minimizing unrelated signal fluctuations. Currently, a diverse set of APs is used to acquire BOLD fMRI data. Here we demonstrate that some fMRI res...

Moulton, Eric A., Michael L. Keaser, Rao P. Gullapalli, Ranjan Maitra, and Joel D. Greenspan. Sex differences in the cerebral BOLD signal response to painful heat stimuli. Am J Physiol Regul Integr Comp Physiol 291: R257–R267, 2006. First published April 6, 2006; doi:10.1152/ajpregu.00084.2006.—There are limited data addressing the question of sex differences in pain-related cerebral processing...