098 Effects of Metameric Display-Light on Alertness, Vigilance and Melatonin

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A40-A41
Author(s):  
Isabel Schöllhorn ◽  
Oliver Stefani ◽  
Manuel Spitschan ◽  
Robert Lucas ◽  
Christian Cajochen

Abstract Introduction Light emitted from visual displays can acutely increase alertness, improve cognitive performance and suppress melatonin in the evening. Here we tested the influence of different melanopic irradiance levels emitted by a metameric display setting on alertness, vigilance and salivary melatonin levels. Methods In an ongoing study, 37 healthy, male participants have so far completed a 2-week study protocol. Volunteers were assigned to one of four luminance groups which differed in brightness levels (27 cd/m2 - 280 cd/m2). Illuminance ranged between 7 and 85 lx. Within the four groups each volunteer was exposed to a low melanopic (LM) and a high melanopic condition (HM). The LM and HM differed in melanopic irradiance (ca. 3-fold change), but matched in terms of cone excitation (metamers). Before, during and after the light exposure, volunteers performed a psychomotor vigilance task (PVT). Subjective alertness and melatonin levels were continuously measured in half-hourly intervals throughout scheduled wakefulness in the 17-h in lab study. Results Preliminary analysis yielded an overall alerting response in the HM vs. the LM condition (p<0.05) concomitant with a trend of reduced melatonin levels in HM vs. LM (p=0.08). So far, we could not observe a difference in PVT performance for HM and LM (Reaction time responses between 100 and 500 ms). Since we are still lacking statistical power in the ongoing study, we cannot yet satisfactorily interpret interaction effects between melanopic condition and brightness. Conclusion Our data indicate that rather low brightness levels of high melanopic display light impacts alertness and melatonin levels in the evening. Thus, metameric low melanopic display light may be a promising method to attenuate activating properties of evening light on circadian physiology without affecting visual appearance. Support (if any) This project is funded by the Swiss National Science Foundation (SNSF).

2019 ◽  
Vol 51 (7) ◽  
pp. 1044-1062 ◽  
Author(s):  
C Cajochen ◽  
M Freyburger ◽  
T Basishvili ◽  
C Garbazza ◽  
F Rudzik ◽  
...  

LED *Shared senior authors. light sources have a discontinuous light spectrum with a prominent ‘blue’ peak between 450 and 470 nm that influences non-image forming responses in humans. We tested an LED lighting solution mimicking a daylight spectrum on visual comfort, circadian physiology, daytime alertness, mood, cognitive performance and sleep. Fifteen young males twice spent 49 hours in the laboratory under a conventional-LED and under a daylight-LED condition in a balanced cross over design flanked by a baseline and a post-light exposure night. Despite different light spectra, the photopic lux and the correlated colour temperature of the lighting were the same for both LEDs. The colour rendering index and the melanopic strength were 25.3% and 21%, respectively, higher for the daylight LED than the conventional LED. The volunteers had better visual comfort, felt more alert and happier in the morning and evening under daylight LED than conventional LED, while the diurnal melatonin profile, psychomotor vigilance and working memory performance were not significantly different. Delta EEG activity (0.75–4.5 Hz) was significantly higher after daylight-LED than conventional-LED exposure during the post-light exposure night. We have evidence that a daylight-LED solution has beneficial effects on visual comfort, daytime alertness, mood and sleep intensity in healthy volunteers.


2011 ◽  
Vol 300 (3) ◽  
pp. E518-E527 ◽  
Author(s):  
Shadab A. Rahman ◽  
Shai Marcu ◽  
Colin M. Shapiro ◽  
Theodore J. Brown ◽  
Robert F. Casper

The human eye serves distinctly dual roles in image forming (IF) and non-image-forming (NIF) responses when exposed to light. Whereas IF responses mediate vision, the NIF responses affect various molecular, neuroendocrine, and neurobehavioral variables. NIF responses can have acute and circadian phase-shifting effects on physiological variables. Both the acute and phase-shifting effects induced by photic stimuli demonstrate short-wavelength sensitivity peaking ≈450–480 nm. In the current study, we examined the molecular, neuroendocrine, and neurobehavioral effects of completely filtering (0% transmission) all short wavelengths <480 nm and all short wavelengths <460 nm or partially filtering (∼30% transmission) <480 nm from polychromatic white light exposure between 2000 and 0800 in healthy individuals. Filtering short wavelengths <480 nm prevented nocturnal light-induced suppression of melatonin secretion, increased cortisol secretion, and disrupted peripheral clock gene expression. Furthermore, subjective alertness, mood, and errors on an objective vigilance task were significantly less impaired at 0800 by filtering wavelengths <480 nm compared with unfiltered nocturnal light exposure. These changes were not associated with significantly increased sleepiness or fatigue compared with unfiltered light exposure. The changes in molecular, endocrine, and neurobehavioral processes were not significantly improved by completely filtering <460 nm or partially filtering <480 nm compared with unfiltered nocturnal light exposure. Repeated light-dark cycle alterations as in rotating nightshifts can disrupt circadian rhythms and induce health disorders. The current data suggest that spectral modulation may provide an effective method of regulating the effects of light on physiological processes.


1990 ◽  
Vol 53 (5) ◽  
pp. 430-440 ◽  
Author(s):  
MIRAY BEKBÖLET

Current research studies carried out on light-induced changes in dairy products, fats and oils, and meat products are reviewed. General factors affecting thus formed off-flavors in these food groups are the intensity of light, exposure interval, type of packaging, and some specific nutritive constituents. In dairy products, riboflavin degradation, losses of vitamin A and C are the major effects, whereas in fats and oils the effective constituents are ß-carotene, tocopherols, the undesirable flavors being related mainly to photosensitized oxidation. In case of meat products, the visual appearance seems to be the most important effect due to the formation of oxidized pigment metmyoglobin from oxymyoglobin upon light exposure. The effects of packaging materials and types on photooxidation are also being discussed for each of the above three food commodity groups.


2017 ◽  
Vol 22 (2) ◽  
pp. 329-335 ◽  
Author(s):  
Takuro Kitamura ◽  
Soichiro Miyazaki ◽  
Hiroshi Kadotani ◽  
Takashi Kanemura ◽  
Harun Bin Sulaiman ◽  
...  

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245428
Author(s):  
Ajay P. Anvekar ◽  
Elizabeth A. Nathan ◽  
Dorota A. Doherty ◽  
Sanjay K. Patole

Objective We aimed to study fatigue and sleep in registrars working 12-hour rotating shifts in our tertiary neonatal intensive unit. Methods and participants This study involved neonatal registrar’s working day (08:00–21:00) and night (20:30–08:30) shifts. Participants maintained a sleep diary, answered a self-reported sleepiness questionnaire assessing subjective sleepiness, and performed a 10-minute psychomotor vigilance task (PVT) at the start and end of each shift. Primary outcomes: (1) Fatigue at the (i) “start vs end” of day and night shifts, (ii) end of the “day vs night” shifts, and (iii) end of “first vs last shift” in block of day and night shifts. (2) Duration and quality of sleep before the “day vs night” shifts. Mean reaction time (RTM), relative coefficient of variation (RTCV), and lapses (reaction time > 500ms) were used as measures of fatigue on PVT. Secondary outcome: Subjective sleepiness (self-reported sleepiness questionnaire) at the ‘start vs end” of day and night shifts. Results Fifteen registrars completed the study. Acuity was comparable for all shifts. (1) Psychomotor responses were impaired at the end vs start of day shifts [RTM (p = 0.014), lapses (p = 0.001)], end vs start of night shifts [RTM (p = 0.007), RTCV (p = 0.003), lapses (p<0.001)] and end of night vs day shifts [RTM (p = 0.007), RTCV (p = 0.046), lapses (p = 0.001)]. Only lapses were significantly increased at the end of the last (p = 0.013) vs first shift (p = 0.009) in a block of day and night shifts. (2) Duration of sleep before the night (p = 0.019) and consecutive night shifts was decreased significantly (p = 0.034). Subjective sleepiness worsened after day (p = 0.014) and night shifts (p<0.001). Conclusion Fatigue worsened after the 12-hour day and night shifts with a greater change after night shifts. Lapses increased after block of day and night shifts. Sleep was decreased before night shifts. Our findings need to be confirmed in larger studies.


Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2176
Author(s):  
Ikuyo Imayama ◽  
Bilgay Izci Balserak ◽  
Ahana Gupta ◽  
Tomas Munoz ◽  
Manassawee Srimoragot ◽  
...  

It is unclear if the response to positive airway pressure (PAP) treatment is different between African American (AA) and European Americans (EA). We examined whether race modifies the effects of PAP on sleep and daytime function. We assessed Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire, Psychomotor Vigilance Task and actigraphy in 185 participants with moderate-to-severe obstructive sleep apnea before and 3–4 months after PAP treatment. The participants were middle-aged (mean, 55.1 years), 83.8% men and 60.5% AA. Linear regression models were used to examine the effect of race on outcomes. The AA had smaller reductions in ESS (mean change (95% confidence interval, CI) AA, −2.30 [−3.35, −1.25] vs. EA, −4.16 [−5.48, −2.84] and frequency of awakenings (AA, −0.73 [−4.92, 3.47] vs. EA, −9.35 [−15.20, −3.51]). A race × PAP usage interaction term was added to the model to examine if the change in outcomes per 1 h increase in PAP usage differed by race. AA exhibited greater improvement in wake after sleep onset (β (95% CI) AA, −8.89[−16.40, −1.37] vs. EA, 2.49 [−4.15, 9.12]) and frequency of awakening (β (95% CI) AA, −2.59 [−4.44, −0.75] vs. EA, 1.71 [−1.08, 4.50]). The results indicate the importance of race in evaluating outcomes following PAP treatment.


2012 ◽  
Vol 7 (4) ◽  
pp. 157-162
Author(s):  
Vanita C Ramrakhiyani ◽  
Abhijit G Deshpande ◽  
Prajakta A Deshpande ◽  
Prasad C Karnik

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