Transcranial infrared laser stimulation enhances cross-frequency phase-amplitude coupling of brain oscillations in vivo measured by electroencephalography (Conference Presentation)

2019 ◽  
Author(s):  
Xinlong Wang ◽  
Hanli Liu ◽  
Hashini K. Wanniarachchi ◽  
Francisco Gonzalez-Lima
Keyword(s):  
Infrared Laser ◽  
Brain Oscillations ◽  
Laser Stimulation ◽  
Phase Amplitude ◽  
Frequency Phase

scholarly journals A statistical framework to assess cross-frequency coupling while accounting for confounding analysis effects

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Jessica K Nadalin ◽  
Louis-Emmanuel Martinet ◽  
Ethan B Blackwood ◽  
Meng-Chen Lo ◽  
Alik S Widge ◽  
...  
Keyword(s):  
High Frequency ◽  
Statistical Power ◽  
Brain Activity ◽  
Low Frequency ◽  
Modeling Framework ◽  
Frequency Coupling ◽  
Phase Amplitude ◽  
Cross Frequency Coupling ◽  
Frequency Phase

Cross frequency coupling (CFC) is emerging as a fundamental feature of brain activity, correlated with brain function and dysfunction. Many different types of CFC have been identified through application of numerous data analysis methods, each developed to characterize a specific CFC type. Choosing an inappropriate method weakens statistical power and introduces opportunities for confounding effects. To address this, we propose a statistical modeling framework to estimate high frequency amplitude as a function of both the low frequency amplitude and low frequency phase; the result is a measure of phase-amplitude coupling that accounts for changes in the low frequency amplitude. We show in simulations that the proposed method successfully detects CFC between the low frequency phase or amplitude and the high frequency amplitude, and outperforms an existing method in biologically-motivated examples. Applying the method to in vivo data, we illustrate examples of CFC during a seizure and in response to electrical stimuli.

Non-invasive in vivo infrared laser spectroscopy to analyse endogenous oxy-haemoglobin, deoxy-haemoglobin, and blood volume in the rat CNS

2005 ◽  
Vol 145 (1-2) ◽  
pp. 11-22 ◽  
Author(s):  
Francesco Crespi ◽  
Andrea Bandera ◽  
Maurizio Donini ◽  
Christian Heidbreder ◽  
Luigi Rovati
Keyword(s):  
Blood Volume ◽  
Laser Spectroscopy ◽  
Infrared Laser ◽  
Non Invasive ◽  
Infrared Laser Spectroscopy ◽  
Rat Cns

scholarly journals Cross-frequency Phase–Amplitude Coupling as a Mechanism for Temporal Orienting of Attention in Childhood

2018 ◽  
Vol 30 (4) ◽  
pp. 594-602 ◽  
Author(s):  
Giovanni Mento ◽  
Duncan E. Astle ◽  
Gaia Scerif
Keyword(s):  
Inverse Correlation ◽  
Human Cognition ◽  
Response Preparation ◽  
Strongly Coupled ◽  
Oscillatory Dynamics ◽  
Beta Power ◽  
Temporal Intervals ◽  
Phase Amplitude ◽  
Frequency Phase ◽  
Temporal Orienting

Temporal orienting of attention operates by biasing the allocation of cognitive and motor resources in specific moments in time, resulting in the improved processing of information from expected compared with unexpected targets. Recent findings have shown that temporal orienting operates relatively early across development, suggesting that this attentional mechanism plays a core role for human cognition. However, the exact neurophysiological mechanisms allowing children to attune their attention over time are not well understood. In this study, we presented 8- to 12-year-old children with a temporal cueing task designed to test (1) whether anticipatory oscillatory dynamics predict children's behavioral performance on a trial-by-trial basis and (2) whether anticipatory oscillatory neural activity may be supported by cross-frequency phase–amplitude coupling as previously shown in adults. Crucially, we found that, similar to what has been reported in adults, children's ongoing beta rhythm was strongly coupled with their theta rhythm and that the strength of this coupling distinguished validly cued temporal intervals, relative to neutral cued trials. In addition, in long trials, there was an inverse correlation between oscillatory beta power and children's trial-by-trial reaction, consistent with oscillatory beta power reflecting better response preparation. These findings provide the first experimental evidence that temporal attention in children operates by exploiting oscillatory mechanism.

Evaluation of an infrared laser-Doppler blood flowmeter

1987 ◽  
Vol 252 (6) ◽  
pp. G832-G839 ◽  
Author(s):  
A. P. Shepherd ◽  
G. L. Riedel ◽  
J. W. Kiel ◽  
D. J. Haumschild ◽  
L. C. Maxwell
Keyword(s):  
Rotational Velocity ◽  
Rotating Disk ◽  
Tissue Perfusion ◽  
Infrared Laser ◽  
Blood Oxygenation ◽  
Laser Doppler ◽  
Laser Doppler Velocimeter ◽  
Flow Signal

Several laser-Doppler blood flowmeters are now commercially available; however, only one utilizes an infrared laser diode (Laserflo, TSI, St. Paul, MN). Because of this and other unique features such as its microprocessor-based signal analyzer, we evaluated this device's ability to measure tissue perfusion. Initially, we determined whether laser illumination directly affected the microvasculature. Intravital microscopic observations in the hamster cremaster muscle indicated that neither He-Ne nor infrared laser light affected the diameters of arterioles that were responsive to vasoactive agents. To test the flowmeter for linearity and repeatability, we used a rotating disk to simulate a light-scattering, flowing medium. The "flow" signal was highly correlated (r = 0.99) with the rotational velocity of the disk, was consistent among flow probes, and showed a high degree of reproducibility. The second model consisted of microsphere suspensions pumped through cuvettes. The laser-Doppler velocimeter (LDV) flow signal was linear with respect to pump output. With red blood cells in the perfusate, we examined the effects of blood oxygenation on the flowmeter's performance. The LDV flow signal was unaffected by changes in blood oxygenation. We evaluated linearity in vivo in isolated, perfused rat livers and in isolated canine gastric flaps. We observed linear relationships between total flow and laser-Doppler flow measured on the surface of the liver (r = 0.98) and in the gastric mucosa (r = 0.98), but the slopes of the relationships between total and local LDV flow showed considerable variability not noted in the in vitro studies.(ABSTRACT TRUNCATED AT 250 WORDS)

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