Featured Research

from universities, journals, and other organizations

Nocturnal alertness improves after exposure to milliseconds of bright light flashes

Date:
June 15, 2010
Source:
American Academy of Sleep Medicine
Summary:
Subjective sleepiness decreased and objective nighttime alertness improved after participants received a two-millisecond pulse of bright light once per minute for 60 minutes. Flash exposure, as compared with darkness, elicited significant improvement in self-rated alertness and a significant 57-millisecond improvement in median reaction time on the auditory Psychomotor Vigilance Test, compared with no significant improvement after 60 minutes of darkness.

Exposure to extraordinarily brief, millisecond flashes of bright light improves alertness at night, according to a research abstract presented June 7, 2010, in San Antonio, Texas, at SLEEP 2010, the 24th annual meeting of the Associated Professional Sleep Societies LLC.

Results indicate that subjective sleepiness decreased and objective nighttime alertness improved after participants received a two-millisecond pulse of bright light once per minute for 60 minutes. Flash exposure, as compared with darkness, elicited significant improvement in self-rated alertness and a significant 57-millisecond improvement in median reaction time on the auditory Psychomotor Vigilance Test, compared with no significant improvement after 60 minutes of darkness. This was accompanied by significant changes in the faster frequencies of the EEG following exposure to the flashes.

"We found it shocking that light exposure as brief as a few milliseconds could engender changes in alertness and brain wave activity," said principal investigator Jamie M. Zeitzer, PhD, assistant professor in the department of psychiatry and behavioral sciences at Stanford University in Palo Alto, Calif. "These results change the manner in which we think about the brain's capacity to respond to light."

The randomized crossover study involved seven people who were tested two times, with the sessions separated by more than two weeks. In each testing condition they were wakened two hours after their typical bedtime for stimulus administration. Once they were exposed to an hour of darkness, and once they were exposed to a total of 120 milliseconds of bright light pulses during an hour of darkness. Vigilance was measured immediately before and at the end of the 60-minute stimulus.

According to the American Academy of Sleep Medicine, the solar light-dark cycle is the primary environmental time cue for synchronizing the circadian system to the 24-hour day. Artificial light absorbed by visual photoreceptors also can affect circadian timing by triggering the suppression of melatonin, a hormone that acts as a "darkness signal."

AASM practice parameters indicate that timed light exposure in the work environment can decrease sleepiness and improve alertness during night shift work. However, bright light therapy typically involves exposure to up to 10,000 lux of light for scheduled periods of 20 minutes or more.

The study was supported by the Air Force Office of Scientific Research, the U.S. Department of Veterans Affairs and Stanford University.


Story Source:

The above story is based on materials provided by American Academy of Sleep Medicine. Note: Materials may be edited for content and length.


Cite This Page:

American Academy of Sleep Medicine. "Nocturnal alertness improves after exposure to milliseconds of bright light flashes." ScienceDaily. ScienceDaily, 15 June 2010. <www.sciencedaily.com/releases/2010/06/100607065557.htm>.
American Academy of Sleep Medicine. (2010, June 15). Nocturnal alertness improves after exposure to milliseconds of bright light flashes. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2010/06/100607065557.htm
American Academy of Sleep Medicine. "Nocturnal alertness improves after exposure to milliseconds of bright light flashes." ScienceDaily. www.sciencedaily.com/releases/2010/06/100607065557.htm (accessed April 18, 2014).

Share This



More Mind & Brain News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Study On Artists' Brain Shows They're 'Structurally Unique'

Study On Artists' Brain Shows They're 'Structurally Unique'

Newsy (Apr. 17, 2014) The brains of artists aren't really left-brain or right-brain, but rather have extra neural matter in visual and motor control areas. Video provided by Newsy
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins