scholarly journals Hemodynamic Response Function Modeling to Determine the Areas with High Blood Supply in Block-Design fMRI Experiments

2019 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Seyedeh Mahboobe Seyed Abbasi ◽  
Mohammad Ali Oghabian ◽  
Seyed Salman Zakariaee ◽  
Abbas Rahimiforoushani
Keyword(s):  
Response Function ◽  
Blood Supply ◽  
Block Design ◽  
Hemodynamic Response ◽  
Hemodynamic Response Function

scholarly journals Modeling of the Hemodynamic Responses in Block Design fMRI Studies

2013 ◽  
Vol 34 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Zuyao Y Shan ◽  
Margaret J Wright ◽  
Paul M Thompson ◽  
Katie L McMahon ◽  
Gabriella G A M Blokland ◽  
...  
Keyword(s):  
Response Function ◽  
Goodness Of Fit ◽  
Block Design ◽  
Onset Time ◽  
Hemodynamic Response ◽  
Fmri Data ◽  
Parameter Estimates ◽  
Block Designs ◽  
Hemodynamic Response Function ◽  
Time To Peak

The hemodynamic response function (HRF) describes the local response of brain vasculature to functional activation. Accurate HRF modeling enables the investigation of cerebral blood flow regulation and improves our ability to interpret fMRI results. Block designs have been used extensively as fMRI paradigms because detection power is maximized; however, block designs are not optimal for HRF parameter estimation. Here we assessed the utility of block design fMRI data for HRF modeling. The trueness (relative deviation), precision (relative uncertainty), and identifiability (goodness-of-fit) of different HRF models were examined and test–retest reproducibility of HRF parameter estimates was assessed using computer simulations and fMRI data from 82 healthy young adult twins acquired on two occasions 3 to 4 months apart. The effects of systematically varying attributes of the block design paradigm were also examined. In our comparison of five HRF models, the model comprising the sum of two gamma functions with six free parameters had greatest parameter accuracy and identifiability. Hemodynamic response function height and time to peak were highly reproducible between studies and width was moderately reproducible but the reproducibility of onset time was low. This study established the feasibility and test–retest reliability of estimating HRF parameters using data from block design fMRI studies.

scholarly journals The brain’s hemodynamic response function rapidly changes under acute psychosocial stress in association with genetic and endocrine stress response markers

2018 ◽  
Vol 115 (43) ◽  
pp. E10206-E10215 ◽  
Author(s):  
Immanuel G. Elbau ◽  
Benedikt Brücklmeier ◽  
Manfred Uhr ◽  
Janine Arloth ◽  
Darina Czamara ◽  
...  
Keyword(s):  
Stress Response ◽  
Response Function ◽  
Genetic Variants ◽  
Psychosocial Stress ◽  
Acute Stress ◽  
Physiological Stress ◽  
Hemodynamic Response ◽  
Hemodynamic Response Function ◽  
Ample Evidence ◽  
Acute Psychosocial Stress

Ample evidence links dysregulation of the stress response to the risk for psychiatric disorders. However, we lack an integrated understanding of mechanisms that are adaptive during the acute stress response but potentially pathogenic when dysregulated. One mechanistic link emerging from rodent studies is the interaction between stress effectors and neurovascular coupling, a process that adjusts cerebral blood flow according to local metabolic demands. Here, using task-related fMRI, we show that acute psychosocial stress rapidly impacts the peak latency of the hemodynamic response function (HRF-PL) in temporal, insular, and prefrontal regions in two independent cohorts of healthy humans. These latency effects occurred in the absence of amplitude effects and were moderated by regulatory genetic variants of KCNJ2, a known mediator of the effect of stress on vascular responsivity. Further, hippocampal HRF-PL correlated with both cortisol response and genetic variants that influence the transcriptional response to stress hormones and are associated with risk for major depression. We conclude that acute stress modulates hemodynamic response properties as part of the physiological stress response and suggest that HRF indices could serve as endophenotype of stress-related disorders.

Motor cortex hemodynamic response function in freely moving subjects recorded via time domain fNIRS

2021 ◽  
Author(s):  
Michele Lacerenza ◽  
Mauro Buttafava ◽  
Lorenzo Spinelli ◽  
Alberto Tosi ◽  
Alberto Dalla Mora ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Response Function ◽  
Time Domain ◽  
Hemodynamic Response ◽  
Hemodynamic Response Function ◽  
Freely Moving

Retinotopic variations of the negative blood-oxygen-level dependent hemodynamic response function in human primary visual cortex

2021 ◽  
Vol 125 (4) ◽  
pp. 1045-1057 ◽  
Author(s):  
Natasha de la Rosa ◽  
David Ress ◽  
Amanda J. Taylor ◽  
Jung Hwan Kim
Keyword(s):  
Visual Cortex ◽  
Response Function ◽  
Complex Dynamics ◽  
Hemodynamic Response ◽  
Blood Oxygen Level Dependent ◽  
Blood Oxygen ◽  
Oxygen Level ◽  
Hemodynamic Response Function ◽  
Blood Oxygen Level ◽  
Early Visual Cortex

We investigate dynamics of the negative hemodynamic response function (nHRF), the negative blood-oxygen-level-dependent (BOLD) response (NBR) evoked by a brief stimulus, in human early visual cortex. Here, we show that the nHRFs are not inverted versions of the corresponding pHRFs. The nHRF has complex dynamics that varied significantly with eccentricity. The results also show shift-invariant temporal linearity does not hold for the NBR.

scholarly journals A cortical rat hemodynamic response function for improved detection of BOLD activation under common experimental conditions

NeuroImage ◽  
2020 ◽  
Vol 208 ◽  
pp. 116446 ◽  
Author(s):  
Henriette Lambers ◽  
Martin Segeroth ◽  
Franziska Albers ◽  
Lydia Wachsmuth ◽  
Timo Mauritz van Alst ◽  
...  
Keyword(s):  
Response Function ◽  
Hemodynamic Response ◽  
Hemodynamic Response Function ◽  
Experimental Conditions

scholarly journals Effects of Hemodynamic Response Function Selection on Rat fMRI Statistical Analyses

2019 ◽  
Vol 13 ◽  
Author(s):  
Shin-Lei Peng ◽  
Chun-Ming Chen ◽  
Chen-You Huang ◽  
Cheng-Ting Shih ◽  
Chiun-Wei Huang ◽  
...  
Keyword(s):  
Response Function ◽  
Hemodynamic Response ◽  
Statistical Analyses ◽  
Hemodynamic Response Function ◽  
Function Selection

scholarly journals Concurrent fMRI and optical measures for the investigation of the hemodynamic response function

2005 ◽  
Vol 54 (2) ◽  
pp. 354-365 ◽  
Author(s):  
Aneurin J. Kennerley ◽  
Jason Berwick ◽  
John Martindale ◽  
David Johnston ◽  
Nikos Papadakis ◽  
...  
Keyword(s):  
Response Function ◽  
Hemodynamic Response ◽  
Hemodynamic Response Function
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