Time in the brain

The Relict of Time by Nel Verbeke, kinetic installation, photography: Alexander Popelier, 2017. The small half bowl in the middle of the wall object rotates at regular intervals. This causes a small quantity of black dust to fall onto the copper plate, and in this way the installation makes the fleeting nature of time visible.

How your brain makes and distorts time

By Marcelino Lopez

An hour in a traffic jam can feel like an eternity, while a lazy Sunday with your sweetheart can go by like a flash of light. How is it that you can experience the same duration of time in such different ways? The reason is that, in a certain sense, time is created by your brain. 

Time is a funny thing. Though you probably don’t doubt the existence of time, you can never actually observe it. Looked at subjectively, the time is always ‘now’. You can only deduce the existence of time from the fact that your perceptions are constantly changing and that you can remember them. Now you’re reading this sentence, and in a moment you’ll be reading the next one. One moment you’re thinking of your mother, but the next moment your mind is on your next appointment.

Time as you experience it is constructed in your brain in a most ingenious way. We may take our ‘healthy’ sense of time for granted, but it is actually quite extraordinary. I don’t need a clock or a calendar to determine that I am writing this on an early spring morning and that I’ve been working on it for about 10 minutes. How does my brain do that?

The perception of time is a complex process in your brain, with different parts of the brain working together to give you a coherent sense of time. Anyone who has used psychedelic drugs knows just how radically this process can be disturbed. What’s more, under the influence of drugs, one’s perception of time can disappear altogether.

In this two-part article, we first look at the factors that create and influence your perception of time: why does time seem to go by so slowly when you’re unhappy, while it flies by in a moment of happiness. In the second part we examine whether we can manipulate our sense of time in such a way that we spend less time being unhappy and more time being happy.

Estimating time without a watch
Even physicists find time difficult to define, but for the purposes of this article we need only distinguish between objective and psychological time. We can measure objective time by following the hands of the clock as they tick by. This kind of time is exactly the same for both you and me. In contrast, psychological time is subjective and says something about how you and I experience that objective time: this is what psychologists call time perception. How does your brain know approximately how much time has passed between the moment that you woke up today and now?

Our whole universe, including your body, is regulated by predictable, cyclic rhythms: day and night, ebb and flow, the four seasons, your breathing and heartbeat, and your sleeping/waking rhythm. All those rhythms give us indications of time. In particular, our body’s internal 24-hour clock – known as our circadian rhythm – helps us determine the time. This biological clock is driven by a small region of the brain called the hypothalamus. Following a 24-hour rhythm, the hypothalamus emits certain hormones that regulate our blood pressure and body temperature to put us to sleep, wake us up, and give us a sensation of hunger.

The surprising thing is that the circadian rhythm is actually 24 hours and 11 minutes long, but this discrepancy gets corrected by other factors such as daylight. In experiments where people spend long periods of time in an isolated space with neither natural nor artificial signals indicating time (such as daylight or clocks), a person’s biological clock gets completely off track. In these sorts of experiments, people eventually end up with a circadian rhythm of 50 hours.

To estimate how much time has elapsed, your brain uses the biological clock and natural rhythms as a frame of reference. Furthermore, all events are full of indicators of how long something lasts. Walking to the shed takes ten seconds, listening to a song takes three minutes, a workout takes one and a half hours, a holiday lasts two weeks, and so forth. Your brain intuitively compares an event (a walk to the supermarket) with your natural rhythms and with past events, allowing you to make a realistic estimate of approximately how much time has gone by in seconds, minutes, hours, days, weeks, and years.

It should come as no surprise that this intuitive way of estimating elapsed time is not as accurate as your watch, especially when it comes to longer periods of time. Consider these research results:

When people aren’t actively conscious of it, it only takes them 55 seconds to estimate that a whole minute has gone by. This estimation of one minute is relatively stable. Estimations for longer periods, such as an hour, are more fickle and less accurate, especially if the biological clock has been tampered with. After spending a long time in an isolated space with no time signals, test subjects ended up with a circadian rhythm of 50 hours and assessed one hour as two whole hours – twice as long as they would have under normal circumstances. Nothing changed in their estimations of a single minute.

Your sense of time depends not only on what you perceive – such as the difference between an exciting thriller and a boring lecture – but also from the state your body and your mind are in.

For example, your body temperature has considerable influence on how you perceive a single hour. Research shows that a few degrees more or less can speed up or slow down a person’s sense of time by 20 percent. For this reason, a patient with a fever will perceive one hour as going by more quickly than they normally would. This may be due to the fact that the speed of chemical processes in our body influences our sense of time.

Another good example of how time gets distorted is during an acute crisis situation. People involved in a traffic accident often perceive the couple of seconds before the collision as much longer. With an impending crash, your body produces a jolt of adrenaline, making your brain work faster and record more impressions per second than normal. On the other end of the spectrum, you have experiences where nothing exciting occurs, such as a traffic jam. In those situations, time seems to tick by much slower than usual.

According to scientists, time perception functions like a U-curve. The two extremes of the curve – consisting of extremely stimulating or very unstimulating periods – are where time usually slows down the most. In between those extremes you can assume the following ‘law’:

The more that is happening either in your brain or around you, and the more attention and processing time your brain needs, the faster time seems to go by.

Knitting Lamp by AtelierNL, photography: Paul Scala. The lampshade consists of a knitting machine which is activated once the light is switched on.

The paradox of our sense of time
When little or nothing seems to be happening, we have the impression that time goes by much more slowly. In calm environments and in the dark, time seems to go by more slowly than is really the case. The more engrossed we are by the environment or the task at hand, the faster time seems to go by.

New experiences and unfamiliar environments speed time up. Just compare a weekend at home with a weekend away in an unfamiliar city. Home is familiar territory, where your brain is working on autopilot, whereas an unfamiliar city is new and demands your attention. But there is also a paradox in our perception of time.

Time flies when you’re having fun, but when your weekend away is over, it seems to have gone on longer than your usual weekend at home. What’s going on is that events in the past are remembered differently from how they are experienced.

Time appears to pass more quickly when you are having fun and having new experiences, but afterwards you remember that time as being longer than how it felt during the moment you experienced it. Why is that? The memories of a predictable weekend at home occupy little space in your memory because they resemble all your previous weekends at home. On a weekend at a new location, your memory creates a large number of new memories, using much more space in your brain. The coffee, the hotel room, the receptionist, the streets, the people you see: everything is new to you. Not only does a weekend away present you with a large number of new stimuli, afterwards you have the feeling that the weekend lasted much longer.

This explains why time seems to go by more quickly as you get older. When you’re young, many experiences still feel new, exciting, and instructive. The older you are, and the more experiences you have had, the less interesting those experiences are to your memory. Our memory is sensitive to the so-called novelty effect. We remember stimuli that are new or different much better than those that are already familiar.

Do you want to be happier in the here and now? And create happy memories in the process? Seek out activities that demand your attention and that allow you to learn or experience something new each time. Psychologists have discovered that people are happiest when they are engrossed in the activity they are engaged in. Psychologists refer to this state as ‘flow’. Dancing, painting, and surfing are just a few examples of activities in which people can experience this ‘timeless’ state. You experience flow when you are focused on a goal in the here and now that demands your complete attention. That focus gives you the ability to become one with what you are doing and to forget all sensation of time. What is needed is a physical or intellectual activity that is suited for your skills but pushes you to your limits. So, it should be just short of being ‘too difficult’. Flow has more or less the same effect on your brain as cocaine. People who engage in these sorts of hobbies possess a powerful ‘instrument of happiness’. Having your attention completely focused on something – and forgetting about time – will make you happy.

Marcelino Lopez (1974) is a Dutch-Spanish psychologist, writer, and therapist. He has written two books about relationships in modern times and is currently working on a critical book on the benefits and drawbacks of the happiness industry. He is interested in moral and ethical issues and shares his insights through a variety of media: print, online, radio, and TV.