Exposure to high mEDI light during the day improves cognitive performance, including information processing speed, working memory and procedural learning, according to research from Harvard Medical School

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Title:	Daytime Exposure to Short Wavelength-Enriched Light Improves Cognitive Performance in Sleep-Restricted College-Aged Adults
Author:	Leilah K. Grant, Brianne A. Kent, Matthew D. Mayer, Robert Stickgold, Steven W. Lockley, Shadab A. Rahman Harvard Medical School, Brigham and Women’s Hospital, Beth Israel Deaconess Medical Center, Boston, MA, United States
Date:	22. February 2021
Source:	https://doi.org/10.3389/fneur.2021.624217
PDF:	Daytime Exposure to Short Wavelength-Enriched Light Improves Cognitive Performance.PDF

Brief summary

An American study demonstrated that daily exposure to white light enriched with short wavelengths and high melanopic illuminance improves data processing speed, working memory, and procedural learning in a motor sequencing task in college students with mild sleep restriction. The study's results further showed that in conditions with high melanopic illuminance, which mimic the spectral composition of sunlight, lower subjective sleepiness was measured compared to the group with low melanopic illuminance. Based on these findings, the researchers suggest that optimizing lighting conditions, such as spectral composition and intensity of light, to resemble sunlight, could significantly benefit cognitive functions in educational and work environments.

Exposure to high mEDI light during the day improves cognitive performance

Thirty-nine undergraduates were divided into four groups by light exposure conditions with equal photopic luminance but different melanopic luminance. The research results showed that higher melanopic luminance correlates with improved cognitive function. The group of participants who worked in the environment with the highest mEDI performed best on tests of processing speed, working memory and procedural learning.

Exposure to higher mEDI light reduces drowsiness compared to lower mEDI light

The study found that exposure to white light with a high melanopic value with a spectral power distribution similar to that of daylight reduced subjective drowsiness compared to light with a low melanopic value and the spectrum of conventional artificial lighting. Participants in the high-melanic spectrum condition group had lower scores on the Karolinska sleepiness scale (KSS), which indicates subjective drowsiness, compared to participants in the low-melanic spectrum condition group.