The relative contribution of rods, cones, and melanopsin to non-image-forming (NIF) responses under light conditions differing in irradiance, duration, and spectral composition remains to be determined in humans. NIF responses to a polychromatic light source may be very different to that predicted from the published human action spectra data, which have utilized narrow band monochromatic light and demonstrated short wavelength sensitivity. To test the hypothesis that only melanopsin is driving NIF responses in humans, monochromatic blue light (lambda(max) 479 nm) was matched with polychromatic white light for total melanopsin-stimulating photons at three light intensities. The ability of these light conditions to suppress nocturnal melatonin production was assessed. A within-subject crossover design was used to investigate the suppressive effect of nocturnal light on melatonin production in a group of diurnally active young male subjects aged 18-35 yrs (24.9+/-3.8 yrs; mean+/-SD; n=11). A 30 min light pulse, individually timed to occur on the rising phase of the melatonin rhythm, was administered between 23:30 and 01:30 h. Regularly timed blood samples were taken for measurement of plasma melatonin. Repeated measures two-way ANOVA, with irradiance and light condition as factors, was used for statistical analysis (n=9 analyzed). There was a significant effect of both light intensity (p<0.001) and light condition (p<0.01). Polychromatic light was more effective at suppressing nocturnal melatonin than monochromatic blue light matched for melanopsin stimulation, implying that the melatonin suppression response is not solely driven by melanopsin. The findings suggest a stimulatory effect of the additional wavelengths of light present in the polychromatic light, which could be mediated via the stimulation of cone photopigments and/or melanopsin regeneration. The results of this study may be relevant to designing the spectral composition of polychromatic lights for use in the home and workplace, as well as in the treatment of circadian rhythm disorders.
This research output has an Altmetric Attention Score of 8. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 07 December 2021.
All research outputs
#5,916,969
of 33,945,077 outputs
Outputs from Chronobiology International: The Journal of Biological & Medical Rhythm Research
#474
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Outputs of similar age
#29,598
of 170,446 outputs
Outputs of similar age from Chronobiology International: The Journal of Biological & Medical Rhythm Research
#94
of 356 outputs
Altmetric has tracked 33,945,077 research outputs across all sources so far. Compared to these this one has done well and is in the 81st percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 1,685 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 23.8. This one has gotten more attention than average, scoring higher than 70% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 170,446 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 81% of its contemporaries.
We're also able to compare this research output to 356 others from the same source and published within six weeks on either side of this one. This one has gotten more attention than average, scoring higher than 73% of its contemporaries.
