Rütger Wever was a German scientist, known for his significant contributions to the field of

Chronobiology Chronobiology is a field of biology that examines timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to solar- and lunar-related rhythms. These cycles are known as biological rhythms. Chronobi ...

, including some of the first experiments on humans in time isolated environments.

Time isolation experiments

Rütger Wever's research focused on the human

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogeno ...

, and how humans behave when placed in an environment where they have no external time cues and are free to choose their own sleep/wake and light/dark schedules. Working with his close collaborator

Jürgen Aschoff Jürgen Walther Ludwig Aschoff (January 25, 1913 – October 12, 1998) was a German physician, biologist and behavioral physiologist. Together with Erwin Bünning and Colin Pittendrigh, he is considered to be a co-founder of the field of chronobio ...

, he had an underground bunker constructed in

Andechs Andechs is a municipality in the district of Starnberg in Bavaria in Germany. It is renowned in Germany and beyond for Andechs Abbey, a Benedictine monastery that has brewed beer since 1455. The monastery brewery offers tours to visitors. The 2 ...

, Germany, for use as a laboratory in which human subjects could be shielded from any external time cues, including variations in light, temperature, and electromagnetic fields. Between 1964 and 1989, this bunker was used to conduct 418 studies in 447 human volunteers. One of the key findings of these experiments was that when free to self-select their schedules, humans run on an approximately 25-h day. More recent experiments have shown that the intrinsic period of the human circadian pacemaker is actually 24.1-24.2 h. However, when subjects are free to self-select their schedules, they choose to go to bed at a much later circadian phase, resulting in a lengthening of the sleep/wake cycle period due to the delaying effects of light exposure at these nighttime circadian phases. Another seminal finding that came out of the Andechs bunker experiments, was the discovery that human sleep/wake cycles could desynchronize from the circadian rhythm of core body temperature. This phenomenon, called 'Spontaneous Internal Desynchrony', typically occurred in subjects after a duration of days to weeks. Strikingly, the length of the sleep/wake cycle varied significantly (from 12 h in some subjects to 68 h in others), while the core body temperature rhythm maintained a period close to 25 h. Under these conditions, subjects were typically unaware of the change in their sleep/wake cycle period. The exact biological basis of this desynchronization remains unknown. The Andechs bunker was used to study human circadian rhythms under a range of conditions, including visual blindness and depression. The results improved understanding of the mechanisms that synchronize the circadian pacemaker to the environment, and had important implications for understanding the cyclicity of many

affective disorders The affective spectrum is a spectrum of affective disorders (mood disorders). It is a grouping of related psychiatric and medical disorders which may accompany bipolar, unipolar, and schizoaffective disorders at statistically higher rates than ...

Mathematical models

Wever's background in

Physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

allowed him to develop some of the first mathematical oscillator models of the human circadian rhythm. This work helped to show that coupled oscillator models can reproduce many of the features of Spontaneous Internal Desynchrony, and set the groundwork for later development of more sophisticated models.

References

{{DEFAULTSORT:Wever, Rutger 2010 deaths Chronobiologists 20th-century German biologists