Improved Detection of Event-Related Functional MRI Signals Using Probability Functions

Hagberg, Gisela E.; Zito, Giancarlo; Patria, Fabiana; Sanes, Jerome N.

doi:10.1006/nimg.2001.0880

Cited by 104 publications

(75 citation statements)

References 39 publications

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“…The event train for the event-related part was generated with interstimulus intervals (ISIs) taken from a uniform permuted distribution between 6 Â TR = 2.64 seconds and 26 Â TR = 11.44 seconds in 1 Â TR steps (Burock et al, 1998;Hagberg et al, 2001). In total, 61 stimuli were presented with a stimulus duration of 250 ms (two 125 ms opposing checkerboard frames) and a mean ISI of 7.04 seconds.…”

Section: Functional Paradigmmentioning

confidence: 99%

Cortical Depth-Dependent Temporal Dynamics of the BOLD Response in the Human Brain

Siero

Petridou

Hoogduin

et al. 2011

J Cereb Blood Flow Metab

127

134

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Recent animal studies at high field have shown that blood oxygen level-dependent (BOLD) contrast can be specific to the laminar vascular architecture of the cortex, by differences in its temporal dynamics in reference to cortical depth. In this study, we characterize the temporal dynamics of the hemodynamic response (HDR) across cortical depth in the human primary motor and visual cortex, at 7 T and using very short stimuli and with high spatial and temporal resolution. We find that the shape and temporal dynamics of the HDR changed in an orderly manner across cortical depth. Compared with the pial vasculature, HDRs in deeper gray matter are significantly faster in onset time (by B0.5 second) and peak time (B2 seconds), and are narrower (by B1 second) and with smaller amplitude, in line with the known vascular organization across cortical depth and the transit of deoxygenated blood through the vasculature. The width of the HDR in deeper gray matter was as short as 2.1 seconds, indicating that neurovascular coupling takes place at a shorter timescale than previously reported in the human brain. These findings open the possibility to probe layer-specific hemodynamics and neurovascular coupling mechanisms in human gray matter.

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Section: Functional Paradigmmentioning

confidence: 99%

Cortical Depth-Dependent Temporal Dynamics of the BOLD Response in the Human Brain

Siero

Petridou

Hoogduin

et al. 2011

J Cereb Blood Flow Metab

127

134

View full text Add to dashboard Cite

show abstract

“…The average TOA was thus 5850 msec. The eight TOA values were pseudorandomized across our trial list using a Latin Squares procedure (see Hagberg, Zito, Patria, & Sanes, 2001), such that the first eight trials had a random ordering of the eight TOA values, the next eight trials had a different random ordering, and so forth.…”

Section: Image Collectionmentioning

confidence: 99%

An Event-Related fMRI Investigation of Implicit Semantic Priming

Rissman¹,

Eliassen²,

Blumstein

2003

Journal of Cognitive Neuroscience

239

183

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Abstract& The neural basis underlying implicit semantic priming was investigated using event-related fMRI. Prime-target pairs were presented auditorily for lexical decision (LD) on the target stimulus, which was either semantically related or unrelated to the prime, or was a nonword. A tone task was also administered as a control. Behaviorally, all participants demonstrated semantic priming in the LD task. fMRI results showed that for all three conditions of the LD task, activation was seen in the superior temporal gyrus (STG), the middle temporal gyrus (MTG), and the inferior parietal lobe, with greater activation in the unrelated and nonword conditions than in the related condition. Direct comparisons of the related and unrelated conditions revealed foci in the left STG, left precentral gyrus, left and right MTGs, and right caudate, exhibiting significantly lower activation levels in the related condition. The reduced activity in the temporal lobe suggests that the perception of the prime word activates a lexicalsemantic network that shares common elements with the target word, and, thus, the target can be recognized with enhanced neural efficiency. The frontal lobe reductions most likely reflect the increased efficiency in monitoring the activation of lexical representations in the temporal lobe, making a decision, and planning the appropriate motor response. &

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“…In the first paradigm, the two conditions were distributed at ISI of 3, 6, and 9 sec using a uniform distribution, which has been shown in simulations to provide high response estimation efficiency [Hagberg et al, 2001]. In rapid ER experiments, three or more inter-stimulus intervals are used to provide sufficient simultaneous equations for estimating the hemodynamic response without making prior assumptions about its shape [Josephs et al, 1997;Miezin et al, 2000;Ollinger et al, 2001a].…”

Section: Simulated Experimentsmentioning

confidence: 99%

“…The detection of differences in response magnitude is important in uncovering the functional anatomy of cognitive processes such as priming and subsequent memory Wagner et al, 1998]. Specifically, the ability to detect subtle signal differences in as short an experiment as possible is a desirable goal and has been the subject of several methodological studies to date [Burock and Dale, 2000;Dale, 1999;Friston et al, 1999;Hagberg et al, 2001;Vazquez and Noll, 1998]. …”

Section: Introductionmentioning

confidence: 99%

Stimulus repetition and hemodynamic response refractoriness in event‐related fMRI

Soon

Venkatraman

Chee

2003

Human Brain Mapping

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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 associated with identical faces compared to different faces in bilateral mid-fusiform and right prefrontal regions but not in the calcarine and posterior fusiform regions. Repetition suppression effects contributed significantly to incomplete signal recovery in a region-specific manner. Simulations using empirically derived data suggest that experiments with shorter ISI (average 4.5-6.0 sec) are as sensitive as experiments with intermediate ISI (average 9 sec) in detecting response differences if experimental duration is equivalent. However, designs using intermediate ISI may be more appropriate if the expected difference in responses is small and if the number of suitable stimuli is limited. Hum. Brain Mapping 20:1-12, 2003.

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Improved Detection of Event-Related Functional MRI Signals Using Probability Functions

Cited by 104 publications

References 39 publications

Cortical Depth-Dependent Temporal Dynamics of the BOLD Response in the Human Brain

Cortical Depth-Dependent Temporal Dynamics of the BOLD Response in the Human Brain

An Event-Related fMRI Investigation of Implicit Semantic Priming

Stimulus repetition and hemodynamic response refractoriness in event‐related fMRI

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