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Existence of Initial Dip for BCI: An Illusion or Reality

A tight coupling between the neuronal activity and the cerebral blood flow (CBF) is the motivation of many hemodynamic response (HR)-based neuroimaging modalities. The increase in neuronal activity causes the increase in CBF that is indirectly measured by HR modalities. Upon functional stimulation,...

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Autores principales: Hong, Keum-Shik, Zafar, Amad
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6212489/
https://www.ncbi.nlm.nih.gov/pubmed/30416440
http://dx.doi.org/10.3389/fnbot.2018.00069
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author Hong, Keum-Shik
Zafar, Amad
author_facet Hong, Keum-Shik
Zafar, Amad
author_sort Hong, Keum-Shik
collection PubMed
description A tight coupling between the neuronal activity and the cerebral blood flow (CBF) is the motivation of many hemodynamic response (HR)-based neuroimaging modalities. The increase in neuronal activity causes the increase in CBF that is indirectly measured by HR modalities. Upon functional stimulation, the HR is mainly categorized in three durations: (i) initial dip, (ii) conventional HR (i.e., positive increase in HR caused by an increase in the CBF), and (iii) undershoot. The initial dip is a change in oxygenation prior to any subsequent increase in CBF and spatially more specific to the site of neuronal activity. Despite additional evidence from various HR modalities on the presence of initial dip in human and animal species (i.e., cat, rat, and monkey); the existence/occurrence of an initial dip in HR is still under debate. This article reviews the existence and elusive nature of the initial dip duration of HR in intrinsic signal optical imaging (ISOI), functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS). The advent of initial dip and its elusiveness factors in ISOI and fMRI studies are briefly discussed. Furthermore, the detection of initial dip and its role in brain-computer interface using fNIRS is examined in detail. The best possible application for the initial dip utilization and its future implications using fNIRS are provided.
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spelling pubmed-62124892018-11-09 Existence of Initial Dip for BCI: An Illusion or Reality Hong, Keum-Shik Zafar, Amad Front Neurorobot Neurorobotics A tight coupling between the neuronal activity and the cerebral blood flow (CBF) is the motivation of many hemodynamic response (HR)-based neuroimaging modalities. The increase in neuronal activity causes the increase in CBF that is indirectly measured by HR modalities. Upon functional stimulation, the HR is mainly categorized in three durations: (i) initial dip, (ii) conventional HR (i.e., positive increase in HR caused by an increase in the CBF), and (iii) undershoot. The initial dip is a change in oxygenation prior to any subsequent increase in CBF and spatially more specific to the site of neuronal activity. Despite additional evidence from various HR modalities on the presence of initial dip in human and animal species (i.e., cat, rat, and monkey); the existence/occurrence of an initial dip in HR is still under debate. This article reviews the existence and elusive nature of the initial dip duration of HR in intrinsic signal optical imaging (ISOI), functional magnetic resonance imaging (fMRI), and functional near-infrared spectroscopy (fNIRS). The advent of initial dip and its elusiveness factors in ISOI and fMRI studies are briefly discussed. Furthermore, the detection of initial dip and its role in brain-computer interface using fNIRS is examined in detail. The best possible application for the initial dip utilization and its future implications using fNIRS are provided. Frontiers Media S.A. 2018-10-26 /pmc/articles/PMC6212489/ /pubmed/30416440 http://dx.doi.org/10.3389/fnbot.2018.00069 Text en Copyright © 2018 Hong and Zafar. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neurorobotics
Hong, Keum-Shik
Zafar, Amad
Existence of Initial Dip for BCI: An Illusion or Reality
title Existence of Initial Dip for BCI: An Illusion or Reality
title_full Existence of Initial Dip for BCI: An Illusion or Reality
title_fullStr Existence of Initial Dip for BCI: An Illusion or Reality
title_full_unstemmed Existence of Initial Dip for BCI: An Illusion or Reality
title_short Existence of Initial Dip for BCI: An Illusion or Reality
title_sort existence of initial dip for bci: an illusion or reality
topic Neurorobotics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6212489/
https://www.ncbi.nlm.nih.gov/pubmed/30416440
http://dx.doi.org/10.3389/fnbot.2018.00069
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