Transient and sustained BOLD responses to sustained visual stimulation

K Uludağ - Magnetic resonance imaging, 2008 - Elsevier
Examining the transients of the blood-oxygenation-level-dependent (BOLD) signal using
functional magnetic resonance imaging is a tool to probe basic brain physiology. In addition …

Neural activity-induced modulation of BOLD poststimulus undershoot independent of the positive signal

S Sadaghiani, K Uğurbil, K Uludağ - Magnetic resonance imaging, 2009 - Elsevier
Despite intense research on the blood oxygenation level-dependent (BOLD) signal
underlying functional magnetic resonance imaging, our understanding of its physiological …

Echo-time dependence of the BOLD response transients–a window into brain functional physiology

M Havlicek, D Ivanov, BA Poser, K Uludag - Neuroimage, 2017 - Elsevier
The blood oxygenation level-dependent (BOLD) fMRI response to neuronal activation
results from a complex interplay of induced metabolic and vascular changes. Thus, its …

Dynamics and nonlinearities of the BOLD response at very short stimulus durations

B Yeşilyurt, K Uğurbil, K Uludağ - Magnetic resonance imaging, 2008 - Elsevier
In designing a functional imaging experiment or analyzing data, it is typically assumed that
task duration and hemodynamic response are linearly related to each other. However …

Spatial heterogeneity of the nonlinear dynamics in the FMRI BOLD response

RM Birn, ZS Saad, PA Bandettini - Neuroimage, 2001 - Elsevier
Recent studies of blood oxygenation level dependent (BOLD) signal responses averaged
over a region of interest have demonstrated that the response is nonlinear with respect to …

When more means less: a paradox BOLD response in human visual cortex

VL Marcar, A Straessle, F Girard, T Loenneker… - Magnetic resonance …, 2004 - Elsevier
The predictions of the 'Linear Transfer Model'(LTM) have been tested only by modulating the
frequency of the action potentials while keeping the size of the activated neuronal …

Spatial and temporal differentiation of fMRI BOLD response in primary visual cortex of human brain during sustained visual simulation

WEI Chen, XH Zhu, T Kato, P Andersen… - Magnetic resonance …, 1998 - Wiley Online Library
The blood oxygenation level dependent (BOLD) response during sustained visual
stimulation has been studied by several groups using fMRI with controversial conclusions …

Sustained negative BOLD, blood flow and oxygen consumption response and its coupling to the positive response in the human brain

A Shmuel, E Yacoub, J Pfeuffer, PF Van de Moortele… - Neuron, 2002 - cell.com
Most fMRI studies are based on the detection of a positive BOLD response (PBR). Here, we
demonstrate and characterize a robust sustained negative BOLD response (NBR) in the …

Negative BOLD fMRI response in the visual cortex carries precise stimulus-specific information

D Bressler, N Spotswood, D Whitney - PLoS One, 2007 - journals.plos.org
Sustained positive BOLD (blood oxygen level-dependent) activity is employed extensively in
functional magnetic resonance imaging (fMRI) studies as evidence for task or stimulus …

Analysis of oxygen metabolism implies a neural origin for the negative BOLD response in human visual cortex

BN Pasley, BA Inglis, RD Freeman - Neuroimage, 2007 - Elsevier
The sustained negative blood oxygenation level-dependent (BOLD) response in functional
MRI is observed universally, but its interpretation is controversial. The origin of the negative …