Thank you for your answers. This is Day 0. Tomorrow, Day 1, complete the intervention using light, and as already explained for the next 10 days. You have been told to expose Head only (10 min) or Head & Back (20 min) as just confirmed above. For the "Quick Impressions" group, Day 11 will also present this same series of questions. Feedback from your answers given today will be offered once a few more "Quick Impressions" participants have completed the study and results have been analyzed. You have our contact information should any questions or problems come up. If an urgent need arises, call +32 475 962408.