scholarly journals Increase in Low-Frequency Oscillations in fNIRS as Cerebral Response to Auditory Stimulation with Familiar Music

2021 ◽  
Vol 12 (1) ◽  
pp. 42
Author(s):  
Giulio Bicciato ◽  
Emanuela Keller ◽  
Martin Wolf ◽  
Giovanna Brandi ◽  
Sven Schulthess ◽  
...  
Keyword(s):  
Near Infrared ◽  
Spectral Power ◽  
Low Frequency ◽  
Signal Recognition ◽  
Brain Response ◽  
Cognitive Response ◽  
Low Frequency Oscillations ◽  
Environmental Stimulation ◽  
Frequency Domain Approach ◽  
External Stimuli

Recognition of typical patterns of brain response to external stimuli using near-infrared spectroscopy (fNIRS) may become a gateway to detecting covert consciousness in clinically unresponsive patients. This is the first fNIRS study on the cortical hemodynamic response to favorite music using a frequency domain approach. The aim of this study was to identify a possible marker of cognitive response in healthy subjects by investigating variations in the oscillatory signal of fNIRS in the spectral regions of low-frequency (LFO) and very-low-frequency oscillations (VLFO). The experiment consisted of two periods of exposure to preferred music, preceded and followed by a resting phase. Spectral power in the LFO region increased in all the subjects after the first exposure to music and decreased again in the subsequent resting phase. After the second music exposure, the increase in LFO spectral power was less distinct. Changes in LFO spectral power were more proGfirst music exposure and the repetition-related habituation effect strongly suggest a cerebral origin of the fNIRS signal. Recognition of typical patterns of brain response to specific environmental stimulation is a required step for the concrete validation of a fNIRS-based diagnostic tool.

scholarly journals Spontaneous Low-Frequency Oscillations Decline in the Aging Brain

2004 ◽  
Vol 24 (10) ◽  
pp. 1183-1191 ◽  
Author(s):  
Matthias L. Schroeter ◽  
Ole Schmiedel ◽  
D. Yves von Cramon
Keyword(s):  
Near Infrared ◽  
Visual Stimulation ◽  
Vascular System ◽  
Low Frequency ◽  
Aging Brain ◽  
Functional Near Infrared Spectroscopy ◽  
Low Frequency Oscillations ◽  
Total Hemoglobin ◽  
Power Spectral ◽  
Spontaneous Oscillations

It is well known that aging leads to a degeneration of the vascular system. Hence, one may hypothesize that spontaneous oscillations decrease in the cerebral microvasculature with aging. Accordingly, the authors investigated the age dependency of spontaneous oscillations in the visual cortex during rest and functional activation. Functional near-infrared spectroscopy was used because it is particularly sensitive to the microvasculature. Visual stimulation led to an increase of oxyhemoglobin, total hemoglobin, and a decrease of deoxyhemoglobin, without any influence of age. Peaks of normalized power spectral density were detected for spontaneous low-frequency (0.07 to 0.11 Hz) and very-low-frequency (0.01 to 0.05 Hz) oscillations, with a higher amplitude for oxyhemoglobin than for deoxyhemoglobin. Spontaneous low-frequency oscillations of oxyhemoglobin and deoxyhemoglobin declined strongly with aging during both rest and visual stimulation. Reduction of spontaneous low-frequency oscillations might indicate a declining spontaneous activity in microvascular smooth muscle cells, in conjunction with an increased vessel stiffness with aging.

scholarly journals Spontaneous Slow Hemodynamic Oscillations are Impaired in Cerebral Microangiopathy

2005 ◽  
Vol 25 (12) ◽  
pp. 1675-1684 ◽  
Author(s):  
Matthias L Schroeter ◽  
Markus M Bücheler ◽  
Christoph Preul ◽  
Rainer Scheid ◽  
Ole Schmiedel ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Low Frequency ◽  
Common Finding ◽  
Vascular Risk ◽  
Functional Near Infrared Spectroscopy ◽  
Low Frequency Oscillations ◽  
Cerebral Microangiopathy ◽  
Spontaneous Oscillations

Small-vessel disease or cerebral microangiopathy (CMA) is a common finding in elderly people. It is related to a variety of vascular risk factors and may finally lead to subcortical ischemic vascular dementia. Because vessel stiffness is increased, we hypothesized that slow spontaneous oscillations are reduced in cerebral hemodynamics. Accordingly, we examined spontaneous oscillations in the visual cortex of 13 patients suffering from CMA, and compared them with 14 agematched controls. As an imaging method we applied functional near-infrared spectroscopy, because it is particularly sensitive to the microvasculature. Spontaneous low-frequency oscillations (LFOs) (0.07 to 0.12 Hz) were specifically impaired in CMA in contrast to spontaneous very-low-frequency oscillations (0.01 to 0.05 Hz), which remained unaltered. Vascular reagibility was reduced during visual stimulation. Interestingly, changes were tightly related to neuropsychological deficits, namely executive dysfunction. Vascular alterations had to be attributed mainly to the vascular risk factor arterial hypertension. Further, results suggest that the impairments might be, at least partly, reversed by medical treatment such as angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers. Results indicate that functional near-infrared spectroscopy may detect changes in the microvasculature due to CMA, namely an impairment of spontaneous LFOs, and of vascular reagibility. Hence, CMA accelerates microvascular changes due to aging, leading to impairments of autoregulation.

scholarly journals Low frequency oscillations in cephalic vessels assessed by near infrared spectroscopy

2012 ◽  
Vol 42 (11) ◽  
pp. 1180-1188 ◽  
Author(s):  
Dorte Phillip ◽  
Henrik W Schytz ◽  
Juliette Selb ◽  
Stephen Payne ◽  
Helle K Iversen ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Low Frequency ◽  
Low Frequency Oscillations
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