sj-docx-1-jbr-10.1177_07487304241226466 – Supplemental material for The Impact of Pupil Constriction on the Relationship Between Melanopic EDI and Melatonin Suppression in Young Adult Males

Supplemental material, sj-docx-1-jbr-10.1177_07487304241226466 for The Impact of Pupil Constriction on the Relationship Between Melanopic EDI and Melatonin Suppression in Young Adult Males by Isabel Schöllhorn, Oliver Stefani, Robert J. Lucas, Manuel Spitschan, Christian Epple and Christian Cajochen in Journal of Biological Rhythms</p

Protocol design.

<p>Light exposure at 6500K (blue bar), 2500K (orange bar) and 3000K (yellow bar).</p

Correlations between salivary melatonin and PVT RT and GO/NOGO RT for light at 6500K, 2500K and 3000K.

<p>Correlations between salivary melatonin and PVT RT and GO/NOGO RT for light at 6500K, 2500K and 3000K.</p

Salivary melatonin during pre-light, 2-h light (grey bar) at 6500K, 2500K and 3000K, and post-light.

<p>* p<0.05.</p

Mental effort, visual well-being and glare/brightness during pre-light, 2-h light (grey bar) at 6500K, 2500K and 3000K, and post-light.

<p>* p<0.05.</p

Sleepiness and well-being during pre-light, 2-h light (grey bar) at 6500K, 2500K and 3000K, and post-light.

<p>* p<0.05.</p

Spectral composition (light wavelength by Irradiance µV²/(cm²x nm) of light at 6500K (blue line), 2500K (orange line) and 3000K (yellow line).

<p>Spectral composition (light wavelength by Irradiance µV²/(cm²x nm) of light at 6500K (blue line), 2500K (orange line) and 3000K (yellow line).</p

Distribution of RT, PVT median RT, PVT fastest RT and GO/NOGO RT during pre-light, 2-h light (grey bar) at 6500K, 2500K and 3000K.

<p>* p<0.05.</p

Chronic Artificial Blue-Enriched White Light Is an Effective Countermeasure to Delayed Circadian Phase and Neurobehavioral Decrements

<div><p>Studies in Polar Base stations, where personnel have no access to sunlight during winter, have reported circadian misalignment, free-running of the sleep-wake rhythm, and sleep problems. Here we tested light as a countermeasure to circadian misalignment in personnel of the Concordia Polar Base station during the polar winter. We hypothesized that entrainment of the circadian pacemaker to a 24-h light-dark schedule would not occur in all crew members (n = 10) exposed to 100–300 lux of standard fluorescent white (SW) light during the daytime, and that chronic non-time restricted daytime exposure to melanopsin-optimized blue-enriched white (BE) light would establish an a stable circadian phase, in participants, together with increased cognitive performance and mood levels. The lighting schedule consisted of an alternation between SW lighting (2 weeks), followed by a BE lighting (2 weeks) for a total of 9 weeks. Rest-activity cycles assessed by actigraphy showed a stable rest-activity pattern under both SW and BE light. No difference was found between light conditions on the intra-daily stability, variability and amplitude of activity, as assessed by non-parametric circadian analysis. As hypothesized, a significant delay of about 30 minutes in the onset of melatonin secretion occurred with SW, but not with BE light. BE light significantly enhanced well being and alertness compared to SW light. We propose that the superior efficacy of blue-enriched white light versus standard white light involves melanopsin-based mechanisms in the activation of the non-visual functions studied, and that their responses do not dampen with time (over 9-weeks). This work could lead to practical applications of light exposure in working environment where background light intensity is chronically low to moderate (polar base stations, power plants, space missions, etc.), and may help design lighting strategies to maintain health, productivity, and personnel safety.</p></div

Impact of BE versus SW light on each participant's phase shift, subjective well being and alertness.

<p>Results were normalized to week SW1. Circadian phase advances (positive phase shifts) and delays (negative phase shifts) and increases and decreases in well being and alertness were averaged over the weeks of the same light condition (SW versus BE). <b>A</b>. On average DLMOs were significantly delayed during SW light weeks compared to BE light weeks (p<0.05). Average subjective well being (<b>B</b>) and alertness (<b>C</b>) were significantly increased under BE light weeks compared to SW light weeks (p<0.05).</p