In an experiment by researchers in the United States, some volunteers were subjected to a bright light via a fiber - optic tube strapped behind the knee, while others, wearing the same apparatus, were not.
USA uurijate läbiviidud eksperimendis lasti mõningatele vabatahtlikele katsealustele läbi kiudoptilise toru põlveõndlasse heledat valgust, teistele, kes kandsid sama aparaati, aga mitte.