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144
2000a) Nonlinear responses in fMRI: the Balloon model, Volterra kernels, and other hemodynamics. NeuroImage
- 12:466-77. KJ, Josephs O, Zarahn E, Holmes AP, Rouquette S, Poline J. (2000b) To
"... There is a growing appreciation of the importance of nonlinearities in evoked responses in fMRI, particularly with the advent of event-related fMRI. These nonlinearities are commonly expressed as interactions among stimuli that can lead to the suppression and increased latency of responses to a stim ..."
Abstract
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Cited by 165 (11 self)
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dynamical model of hemodynamic signal transduction in fMRI. Subsequent work by Mandeville et al. (1999) provided important theoretical and empirical constraints on the form of the dynamic relationship between blood flow and volume that underpins the evolution of the fMRI signal. In this paper we combine
Diffusion-weighted spin-echo fMRI at 9.4 T: microvascular/tissue contribution to BOLD signal changes
- Magn. Reson. Med
, 1999
"... The nature of vascular contribution to blood oxygenation level dependent (BOLD) contrast used in functional MRI (fMRI) is poorly understood. To investigate vascular contributions at an ultrahigh magnetic field of 9.4 T, diffusion-weighted fMRI techniques were used in a rat forepaw stimulation model. ..."
Abstract
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Cited by 44 (16 self)
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). The optimal spin-echo time of 40 msec was confirmed from echo-time dependency fMRI studies. The intravascular contribution was examined using a graded diffusion-weighted spin-echo echo-planar imaging technique with diffusion weighting factor (b) valuesofupto 1200 sec/mm2. Relative BOLD signal changes induced
Sources of functional apparent diffusion coefficient changes investigated by diffusion-weighted spin-echo fMRI.
, 2006
"... The mechanism behind previously observed changes in the apparent diffusion coefficient (ADC) during brain activation is not well understood. Therefore, we investigated the signal source and spatial specificity of functional magnetic resonance imaging (fMRI) ADC changes systematically in the visual ..."
Abstract
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Cited by 3 (1 self)
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cortex of cats using diffusion-weighted (DW) spin-echo The measurement of ADC in fMRI is generally achieved by varying the levels of diffusion weighting (usually quantified as b) and then fitting the resulting attenuated signals to a monoexponential decaying function of b. According to the intravoxel
Eventrelated fMRI of the auditory cortex
- Neuroimage
, 1999
"... An event-related protocol was designed to permit auditory fMRI studies minimally affected by the echoplanar noise artifact; a long time interval (TR � 10 s) between each cerebral volume acquisition was combined with stroboscopic data acquisition, and eventrelated curves were reconstructed with a 1-s ..."
Abstract
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Cited by 37 (6 self)
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method appeared effective in minimizing effects of the interaction between scanning noise and experimental auditory stimulation; it adds useful temporal information to the spatial resolution afforded by fMRI in studies of human auditory function, while allowing presentation of auditory stimuli on a
as Measured by fMRI
"... Abstract: The goal of this functional magnetic resonance imaging (fMRI) study was to compare the central effects of electroacupuncture at different frequencies with traditional Chinese manual acupuncture. Although not as time-tested as manual acupuncture, electroacupuncture does have the advantage o ..."
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Abstract: The goal of this functional magnetic resonance imaging (fMRI) study was to compare the central effects of electroacupuncture at different frequencies with traditional Chinese manual acupuncture. Although not as time-tested as manual acupuncture, electroacupuncture does have the advantage
Effect of Hemodynamic Variability on Granger Causality Analysis of fMRI
"... In this work, we investigated the effect of the regional variability of the hemodynamic response on the sensitivity of Granger causality (GC) analysis of functional magnetic resonance imaging (fMRI) data to neuronal causal influences. We simulated fMRI data by convolving a standard canonical hemodyn ..."
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In this work, we investigated the effect of the regional variability of the hemodynamic response on the sensitivity of Granger causality (GC) analysis of functional magnetic resonance imaging (fMRI) data to neuronal causal influences. We simulated fMRI data by convolving a standard canonical
Stimulus repetition and hemodynamic response refractoriness in event-related fMRI
- Hum. Brain Mapp
, 2003
"... Abstract: We investigated the extent of hemodynamic recovery following the paired presentation of either identical or different faces at two different inter-stimulus intervals (ISI). Signal recovery was consistently better at an ISI of 6 sec compared to 3 sec. Significantly less signal recovery was ..."
Abstract
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Cited by 9 (0 self)
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if the expected difference in responses is small and if the number of suitable stimuli is limited. Hum. Brain Mapping 20:1–12, 2003. © 2003 Wiley-Liss, Inc. Key words: event-related fMRI; repetition effects; face processing; experimental design
Non-white noise in fMRI: Does modelling have an impact?
- Neuroimage,
, 2006
"... Abstract The sources of non-white noise in Blood Oxygenation Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) are many. Familiar sources include low-frequency drift due to hardware imperfections, oscillatory noise due to respiration and cardiac pulsation, and residual movement ar ..."
Abstract
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Cited by 36 (1 self)
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artefacts not accounted for by rigid body registration. These contributions give rise to temporal autocorrelation in the residuals of the fMRI signal and invalidate the statistical analysis as the errors are no longer independent. The low-frequency drift is often removed by high-pass filtering, and other
Dynamical cluster analysis of cortical fMRI activation
- NeuroImage
, 1999
"... Localized changes in cortical blood oxygenation during voluntary movements were examined with functional magnetic resonance imaging (fMRI) and evaluated with a new dynamical cluster analysis (DCA) method. fMRI was performed during finger movements with eight subjects on a 1.5-T scanner using single- ..."
Abstract
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Cited by 25 (1 self)
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Localized changes in cortical blood oxygenation during voluntary movements were examined with functional magnetic resonance imaging (fMRI) and evaluated with a new dynamical cluster analysis (DCA) method. fMRI was performed during finger movements with eight subjects on a 1.5-T scanner using single
ORIGINAL PAPER Point-Process Deconvolution of fMRI BOLD Signal Reveals Effective Connectivity Alterations in Chronic Pain Patients
, 2013
"... Abstract It is now recognized that important information can be extracted from the brain spontaneous activity, as exposed by recent analysis using a repertoire of computational methods. In this context a novel method, based on a blind deconvolution technique, is used to analyze potential changes due ..."
Abstract
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due to chronic pain in the brain pain matrix’s effective con-nectivity. The approach is able to deconvolve the hemody-namic response function from spontaneous neural events, i.e., in the absence of explicit onset timings, and to evaluate infor-mation transfer between two regions as a joint probability
Results 1 - 10
of
144