Published 10 August 2022
From John Cantellow, Derby, UK
“Into the blue” comprehensively conveyed the psychological benefits of both green and blue spaces (16 July, p 38). However, I was intrigued by the reference to the calming effects of blue spaces.
We have known for some time that blue has a stimulating, not a calming, effect due to melanopsin receptors in the eye that are particularly sensitive to blue light. This causes excitation of the suprachiasmatic nucleus of the brain, the master biological clock, and releases wake-up hormones, such as cortisol.
For me, this begs the question: what is the physiology that underpins the calming effect of proximity to water?