The search for hidden time
Es fängt gleich mit einem Paradox an: Je mehr man sich mit diesem Thema beschäftigt, desto unklarer wird es. Die Rede ist von der Zeit. Und ausgerechnet so ein rätselhaftes Phänomen will nun eine vom Forschungszentrum Jülich koordinierte Gruppe von Wissenschaftlerinnen und Wissenschaftlern nicht nur besser verstehen, sondern auch aktiv beeinflussen. Ein Blick ins Zeitlabor.
Anna Hoagland was not feeling well. She had a fever, lay in bed with a flu and waited for her husband to finally come back and check on her. The time became long for her, which she let him know when he entered the room at last.
It may be assumed that she regretted her impatience afterwards, for the complaint about his long absence gave her husband a momentous idea – after all, Hudson Hoagland was a scientist to the core. He graduated from Columbia University, the Massachusetts Institute of Technology and from Harvard. He was at the University of Cambridge, would soon take up a chair of physiology at Clark University and eventually co-found the prestigious Worcester Foundation.
His wife’s remark perplexed him, for according to the objective measurements of his watch, he had not been away for long. Since a researcher’s answer to the unexpected is an experiment, after all, Hoagland looked into his wife’s unusual sense of time with a test. Each time he measured her temperature, he had her estimate the duration of one minute – 30 times in total.
The result: for Anna Hoagland, the minutes passed almost twice as slowly as for her healthy husband. When the second hand of his watch had just completed one lap, she felt as if two minutes had already elapsed. The higher her fever was, the faster her internal clock seemed to tick. This curious equation of ‘the faster’ (the subjective clock), ‘the slower’ (time passes) fits well with a subject that has as many paradoxes to offer as time.
With the fact that the perception of time is relative to body temperature, the American physiologist Hoagland discovered an important correlation in the early 1930s. Apparently, the physical state of arousal has a strong influence on whether a moment is experienced as short or long. It follows that our perception of time is not simply derived from the objective indicators of our environment, but is constructed by ourselves to a significant extent. Time is relative – not only from the perspective of physics, but also according to the findings of psychology and brain research.
The subjective stretching of the moment in case of fever is not much more than an unpleasant experience. However, there are situations where this slowdown has a very practical, even vital, benefit.
Schock in Slow Motion
She can still remember a dark shadow coming towards her from the left. Then there was a deafening bang. Andrea K. was driving her car on a country road when another car took her right of way at a blind intersection and crashed into the driver’s side of her car. She veered off the road, broke through a pasture fence and hurtled straight towards a large tree. While the obstacle was coming closer and closer as if in slow motion, she floored the brake pedal, jerked the steering wheel wildly and ultimately pulled the handbrake as well. She was even relieved to discover that there were no horses in the field that day. In the end, the car came to a halt just before the tree. The whole incident had lasted no longer than three seconds. In those three seconds, her life did not flash before her eyes like in a movie. Her thoughts were a great deal more trivial. She was annoyed. She had just had an inspection done and the air conditioning cleaned. She could have saved that money. The car was now totalled.
Such extreme situations are prominent examples of the subjective stretching of the moment. All events seem to be slowing down in this instant. Even those who have not yet experienced such moments of horror know this effect from films. Many filmmakers enjoy using slow motion in emotionally condensed key scenes. In the accident sequence in Claude Sautet’s “The Things of Life”, Michel Piccoli hopes for a good outcome for almost two minutes. In reality, however, the tragic events here are unlikely to have taken more than four seconds. The reason for this slow-motion effect is ultimately the same as for Anna Hoagland’s fever. The physical activation is increased due to the special circumstances and leads to a slower sense of time.
According to Marc Wittmann from the Institute for Frontier Areas of Psychology and Mental Hygiene in Freiburg, an expert in the experience of time, there is a second factor besides physiological activity that leads to the same result. The more we concentrate on time itself, consciously perceiving it, the more stretched it appears to us. There is no need for an accident in order to understand this insight. A really long queue in the supermarket or a full waiting room is enough. Everyone knows this: in moments that force us to pause, time simply does not seem to want to pass.
Wie entsteht unser Zeitgefühl?
But even if decisive factors are known, it is still an open question for science at present as to how exactly our sense of time works. “There are various theories” says Kai Vogeley, scientist at Jülich and Professor of Psychiatry and Psychology at Cologne University Hospital. “But what happens exactly is ultimately still unclear.” Vogeley is spokesperson of the international cooperation project VIRTUALTIMES, which is coordinated by Forschungszentrum Jülich. Funded by the European Union over a period of four years, the project is dedicated to researching and changing the sense of time. “Movement seems to play an important role in experiencing the passing of time. There are also neurobiological models in which, for example, the heartbeat acts as a kind of hand of the circadian clock.”
The solution to the riddle is sophisticated, and the knowledge gained through it should contribute fundamentally to the understanding of human subjectivity. According to Marc Wittmann, who is also involved in the VIRTUALTIMES project, self-confidence and experience of time are closely connected, for example. Vogeley also believes that “physicality, perception of space and that of time are the central determinants that make us self-aware”. Those neurobiological processes that underlie our sense of time also play an important role in the question of the freedom of the human will. This was shown not least by the much-discussed Libet experiments in the early 1980s.
Libet experiments
| The American neurophysiologist Benjamin Libet, who was actually interested in the neural mechanisms of consciousness, found in his experiments that a readiness potential for an action was built up in the brains of his test subjects even before the trial participants became aware of the will to perform the corresponding action – the raising of their hand. An intense scientific controversy arose over the interpretation of his results. While some saw free will disproved by Libet’s experiments, others criticised that the problem posed in his experiment could by no means be compared to a complex decision. Libet himself did not go so far as to question free will altogether. |
The importance of the inner clock cannot really be overestimated. This “metronome” makes us perceive melodies as such in the first place, instead of simply hearing an incoherent sequence of notes in them. It also ensures the right timing for every action and social interaction. “What we call the present lasts about three seconds. Interestingly, this also corresponds to just about the length of a line of poetry or the duration of the social gaze. At least that’s when we find eye contact most pleasant,” explains Kai Vogeley.
It is therefore not surprising that scientists all over the world have long been trying to decipher the mechanics of the circadian clock. Almost nothing seems to be off limits for them in their endeavours. They lock patients in underground bunkers for weeks on end; let them perform dangerous tasks under water; or drop backwards from a 31-meter tower into the depths. Hudson Hoagland, too, did not hesitate to induce an artificial fever in a student, using thermotherapy. But why is it so hard to unravel the mystery of time?
Kommt Zeit, kommt Rätsel
„Was ist also die Zeit? Wenn mich niemand danach fragt, weiß ich es, wenn ich es aber einem, der mich fragt, erklären sollte, weiß ich es nicht.“ Dieser prominente Seufzer des spätantiken Philosophen und Kirchenlehrers Augustinus verdeutlicht nicht nur, dass sich Menschen schon seit einer ganzen Weile den Kopf über dieses rätselhafte Phänomen zerbrechen, er bringt auch seine eigentümliche Ambivalenz zum Ausdruck. Mit der Zeit verhält es sich ein wenig wie mit der Schliere im Augenwinkel. Man nimmt sie zwar wahr, aber sobald man versucht, sie zu fokussieren, verschwindet sie wieder. „In dem Augenblick, in dem jemand anfängt, über Zeit nachzudenken, verändert das die Zeitwahrnehmung. Wenn wir Menschen also im Zusammenhang mit einem Experiment fragen, wie sie Zeit erleben, impliziert das, dass sie darüber nachdenken. Das ist ein großes Problem bei der Untersuchung“, beschreibt Mathis Jording, Doktorand am Institut für Neurowissenschaften und Medizin des Forschungszentrums Jülich, die Tücken der wissenschaftlichen Analyse. Um trotz dieser Hürde zu neuen Erkenntnissen zu gelangen, haben sich die am Projekt VIRTUALTIMES beteiligten Wissenschaftlerinnen und Wissenschaftler einen ungewöhnlichen Ansatz einfallen lassen. Ihre Idee ist dabei nicht nur originell, sondern für die Patienten auch vollkommen gefahrlos.
Mit der VR-Brille auf die innere Uhr geschaut
As the project name already suggests, it has something to do with virtual reality. “It’s about isolating the experience of time as such – that is, making it measurable first and, in a second step, changing it. Virtual reality, or VR for short, offers incredible possibilities here. In this way, we can influence many different aspects of a situation without experiencing it as a pure laboratory situation,” says Jording about the advantages of VR supported methods. Using VR glasses and motion sensors, patients could be transported into any reality. Sensors play an important role in this, as they support the so-called embodiment – the physical aspects of our perception. “It’s not so much about the photorealistic graphics as it is about how well you can or cannot empathise with a situation,” says Jording. Anyone who has ever had the opportunity to watch people with a headset trying to cross a narrow beam over a fictitious gorge will immediately believe him.
How does time come into play in virtual reality? Just like in the real world. The ticking of a clock, the movements of other people, a flock of birds passing by, sunrises or sunsets – all these are only a handful of possible events that signal change and, thus, the passing of time. “Only within the context of virtual reality can we manipulate so many different zeitgebers at the same time,” explains Kai Vogeley. “We’re sort of putting together a workbench here to make the sense of time measurable.”
With MetaChron, as the scientists have christened their “workbench”, they are in a sense reversing the classic approach. Instead of asking directly about the subjective experience, they control the objective conditions and observe the effects. This enables them to relate context and individual perception to each other and derive measurable results from their relation. So, one can imagine MetaChron as a sextant for experiencing time. The difference is that, instead of sun and horizon, MetaChron relates the subjective sense of time and objective parameters.
In addition, this special experimental arrangement offers the opportunity to bring feeling and reality closer together – even if the latter is only virtual in this case. The aim is to catch patients during their individual experience, so to speak. This experience can sometimes deviate very strongly from the references to the world and their rhythm. For instance, there are mental illnesses which have a massive influence on the sense of time.
When life gets out of step
Psychiatrist Kai Vogeley reports of sometimes bizarre disorders of the circadian clock. “People who suffer from depression sometimes say that time passes very slowly or even stands still. This sometimes even makes them think they’re dead.” For manic patients, on the other hand, time flies by. Schizophrenia can also considerably disrupt the sense of time, up to the loss of the time structure consisting of past, present and future.
I have a feeling all day long that is interspersed with fear and that relates to time. I can’t stop thinking that time is passing. As I speak to you now, I think with every word: ‘over’, ‘over’, ‘over’.” This is how a 20-year-old woman suffering from depression describes her sense of time. Her perception almost invariably focuses on transience and finally leads to social alienation. “I can’t understand how people make plans and attach sense to such time specifications and remain totally calm in doing so. I therefore feel alienated from all people, as if I didn’t belong, as if I were completely different.” The young woman’s statements make her distress clear and comprehensible. However, it is something else that is really remarkable about them. They date from the middle of the previous century. The psychiatrist Victor Emil von Gebsattel had recorded them. The relation between mental illness and a disturbed perception of time has been known for a long time. Yet, there are still hardly any therapeutic approaches that take this relation into account.
This is what the VIRTUALTIMES project wants to change. Apart from the primarily analytical concern of better understanding the inner clocks of human beings, Vogeley and the other researchers involved have also set themselves the goal of developing new treatment methods. “The idea is to possibly establish a therapy by modifying time in VR.” Curing depression with VR glasses may seem a bit ambitious at first, but similar approaches have already proven quite successful in other disease patterns, such as anxiety disorders.
Of course, such glasses would have been of little use to the feverish Anna Hoagland. In her case, however, this was not even necessary. After all, her husband took care of her – with compassionate care and the curiosity of a scientist.
By the way, Hudson Hoagland kept his thirst for knowledge throughout his life. A neighbour reported that he once saw Hoagland, well along in his years, standing at an emergency call point. When he asked him if he could help him, he just waved him off and replied that everything was fine – he just wanted to find out how this thing worked.
Philippe Patra