Effects of stimulating frequency of NIR LEDs light irradiation on forehead as quantified by EEG measurements

Near-infrared (NIR) light has been shown to produce a range of physiological effects in humans, however, there is still no agreement on whether and how a single parameter, like the flicker frequency of NIR light, affects the brain. An 810 nm NIR LED was used as the stimulator. Fifty subjects partici...

Full description

Saved in:
Bibliographic Details
Published in:Journal of innovative optical health science 2021-03, Vol.14 (2), p.2050025-1-2050025-12
Main Authors: Yao, Liuye, Qian, Zhiyu, Liu, Yangyang, Fang, Zhou, Li, Weitao, Xing, Lidong
Format: Article
Language:English
Subjects:
Brain
EEG
Electroencephalography
Entropy
Flicker
Forehead
gravity frequency
Irradiation
led light therapy
Light
Light emitting diodes
Light irradiation
Near infrared radiation
near-infrared light
photobiomodulation
Physiological effects
Radiation
relative energy
Research Article
Stimulation
Stimulators
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Near-infrared (NIR) light has been shown to produce a range of physiological effects in humans, however, there is still no agreement on whether and how a single parameter, like the flicker frequency of NIR light, affects the brain. An 810 nm NIR LED was used as the stimulator. Fifty subjects participated in this experiment. Forty subjects were randomly divided into four groups. Each group underwent a 30-minute NIR LED radiation with four different frequencies (i.e., 0 Hz, 5 Hz, 10 Hz and 20 Hz, respectively) on the forehead. The remaining 10 subjects formed the control group, in which they underwent a 30-minute rest period without light radiation. EEG signals of all subjects during each test were recorded. Gravity frequency (GF), relative energy change, and sample entropy were analyzed. The experimental groups had larger GF values compared to the control group. Higher stimulation frequency would cause larger growth of GF ( F = 1 4 . 7 5 , P < 0 . 0 0 1 ). The amplitude of alpha waves relative energy increased, while theta waves decreased remarkably in the experimental groups ( p < 0 . 0 2 ), and the extent of increase/decrease was larger at higher stimulation frequency, compared to that of the control. Sample entropy of electrodes in the frontal areas were much larger than those in other brain areas in the experimental groups ( p < 0 . 0 0 1 ). Larger frequency of the NIR LED light would cause more distinct brain activities in the stimulated areas. It indicates that NIR LED light may have a positive effect on modulating brain activity. These results may help improve the design of photobiomodulation treatments in the future.
ISSN:1793-5458
1793-7205
DOI:10.1142/S179354582050025X