Abstract: 

Sleep remains one of the most fascinating and indispensable biological functions, yet its fundamental purpose is still not fully understood.                If sleep were not essential to survival, its conservation across evolution would represent the greatest mistake of nature. Across species, sleep is remarkably preserved, pointing to critical roles in brain homeostasis, memory consolidation, and systemic physiology. Its regulation relies on a finely tuned interplay between circadian rhythms and homeostatic sleep pressure. When sleep is disrupted through unstable sleep–wake boundaries (parasomnias), abnormal motor activity, or breathing disorders such as sleep apnea, the consequences extend to cognition, metabolism, and cardiovascular health. In this talk, I will explore the key unanswered questions about why we sleep, how sleep disorders can affect our health, and highlight how emerging technologies are reshaping our ability to study and treat them.

Short Bio:

After completing his training in internal medicine, including research stays at the Stanford Sleep Center in Palo Alto and Harvard Medical School, Prof. Heinzer established the sleep research center CIRS in 2006. This center is a collaboration of the University of Lausanne and the University Hospital CHUV, and it is the site of the largest dataset of a population-based sleep cohort. Today, Prof. Heinzer and his team conduct over 1000 sleep examinations annually. His research focuses on the physiology and epidemiology of various sleep disorders  - including apnea, insomnia, hypersomnia, parasomnia. He also dedicates part of his work to studying sleep under extreme conditions such as high altitude, solo sailing, or long-duration flights as in the case of Solar Impulse. 

This is the first of two CERN Academic Training Lectures on Human Sleep. The second will be given by Francesca Siclari on 20 January 2026 -         "The Neuroscience of Dreaming"