Human Circadian Phenotyping

This intensive five-day course provides a hands-on introduction to contemporary methods for measuring human circadian physiology in laboratory and real-world settings. Focusing on salivary melatonin, dim light melatonin onset, rest-activity cycles, and personal light exposure, the course introduces participants to the principles and practice of human circadian phenotyping. Through a combination of taught sessions, laboratory demonstrations, guided data collection, and home-based monitoring, participants will learn how circadian timing can be assessed and how it is shaped by environmental light exposure and daily behavior. A central feature of the course is that participants will collect data on themselves during the evening sessions using selected circadian phenotyping methods and will analyse these data as part of the course. Data analysis will be carried out using LightLogR and dlmoR, providing participants with practical experience in open-source tools for the processing and interpretation of light exposure, rest-activity, and melatonin timing data. This direct engagement with data collection and interpretation is intended to provide participants with first-hand experience of the methodological, practical, and analytical challenges involved in human circadian research. The course also introduces participants to the design of human circadian experiments, including issues of standardization, participant compliance, data quality, reproducibility, transparent reporting, and structured approaches to research data and metadata. By combining controlled laboratory sessions with ecological monitoring in everyday life, the course offers an immersive introduction to modern methods in circadian and sleep research. Participants will be provided with an extensive reading list of academic articles and other resources in advance of the course. Completion of this preparatory reading is mandatory. In addition, students will be asked to prepare a literature summary before the course. Each participant will be assigned a different focus area, allowing the cohort as a whole to engage with a broader range of topics relevant to human circadian phenotyping. Focus areas will be assigned on 15 August 2026. In the virtual-only period between 17 August 2026 and 11 September 2026 (before the start of the course), students are expected to participate in two 1.5h online meetings, with an expected workload of 3h/week before the course starts.

By the end of the course, participants will be able to: • explain the physiological basis of human circadian timing and the role of melatonin as a marker of circadian phase • describe the principles, strengths, and limitations of dim light melatonin onset as a method for circadian phenotyping • collect, handle, and document salivary melatonin samples using standardized procedures • explain how evening light exposure influences melatonin secretion and circadian physiology • use actigraphy and personal light exposure monitoring to characterize rest-activity cycles and environmental light exposure • compare laboratory-based and home-based approaches to circadian measurement, including their advantages and limitations • identify key considerations in the design and conduct of human circadian experiments, including standardization, participant compliance, and data quality • implement good practices in data handling, curation, and quality control for circadian phenotyping datasets • apply principles of reproducible research, transparent documentation, open reporting, and structured knowledge representation to human circadian studies • interpret melatonin, actigraphy, and light exposure data in relation to circadian timing and daily behavior

Written report (2000 words). Further guidance on the format and expectations for this report will be provided during the course. Participants who successfully complete the course requirements will receive a course certificate at the end of the course.

Dates: Monday, 17 August to Friday, 11 September 2026 (virtual preparatory period); Monday, 14 September to Friday, 18 September 2026 (in-person course). The course is intended for graduate students at MSc and PhD level who are interested in learning methods in human circadian phenotyping. Applicants should be working in chronobiology, sleep research, or adjacent disciplines in which these methods are relevant to their current or planned research. Participation is free of charge, but places are limited and admission is selective. Applications, submitted via email to manuel.spitschan@tuebingen.mpg.de, should include a curriculum vitae of no more than two pages and a letter of motivation of no more than one page. The application deadline is 30 June 2026. The letter of motivation should explain the applicant’s academic background, current stage of study, and research interests, and should clearly describe why participation in the course would be relevant to their work. Applicants should also indicate how the methods covered in the course connect to their interests in chronobiology, sleep research, or a related field, and what they hope to gain from participating. Selection will be based on the applicant’s motivation, the relevance of the course to their current or future research, and the overall fit with the course topic and participant cohort.

• Participants will be provided with an extensive reading list of academic articles and other resources in advance of the course. Completion of this preparatory reading is mandatory. In addition, students will be asked to prepare a literature summary before the course.

Taught sessions, laboratory demonstrations, guided data collection and home-based monitoring. Location: Max Planck Institute for Biological Cybernetics, Tübingen, Germany There is no course fee. However, participants are responsible for arranging and covering their own travel and accommodation costs. No travel grants are available, no financial support for accommodation can be provided, and no support for visa applications can be offered. If needed, a formal letter of admission can be issued to selected applicants. No catering will be provided during the course. Participants may wish to note that the Max Planck House in Tübingen has a canteen and may also offer accommodation opportunities. In terms of workload, the course is roughly comparable to 5 ECTS credits, taking into account contact hours, mandatory preparatory reading, the advance literature summary, participation in data collection and analysis, and the written report. Any formal recognition of ECTS or local credit equivalence remains the responsibility of the participant’s home institution.