Time is a very important concept to us, our lives are framed by and hang on the perception of it. We could discuss time’s existence from the viewpoint of Physics (Biocentrism propounds that all moments in time happen simultaneously), or philosophy, or its importance to us, but I’ll keep these notes to perception.
Chronoception refers to the subjective experience of time. We naturally have “perceived duration,” the perceived time interval between two successive events. The concept of time may seem like a human construct, but it is also one that is reflected in the rhythms of nature and other creatures.
Both plants and animals possess inner clocks that tell them when to flower, seed, germinate, go dormant, migrate, hibernate, spawn, or metamorphosize. Species on Earth have evolved by the seasons and in some cases by strategies that require tracking long time intervals (Cicada). The only difference is that humans are consciously aware of the passing of time. Here are some of the time intervals that human brains naturally track:
- Moment (short): twinkling of an eye – two visual stimuli can be perceived simultaneous within five milliseconds.
- Moment (long): a heart beat or two.
- Brief period of time: “a few minutes” in modern terms.
- A part of the day: a breaking of the day into a series of time intervals (12th or 24th) goes back to the Babylonians and Egyptians. It is difficult to determine its relevance to native/tribal cultures, but all “civilizations” use some interval to mark the hours of the day.
- Circadian (or ultradian rhythm) daily rhythm: the raising and setting of the sun: dawn, midday, dusk, night. The presence and absence of sunlight plays and essential role in this perception and can prove confusing to our bodies when we travel quickly from north to south (or vice versa) or along mutiple time zones.
- Month: the phases of the moon (association – menstrual cycles).
- Seasonal changes: Spring, Summer, Autumn and Winter.
- Ages of life: as Shakespeare named them the seven ages of man, and most of us recognize at least infant, child, adolescence, prime youth, middle age, old age.
- Generational: we do not experience, but can easily conceptualize, the time interval for multiple generations (at least a few).
- Long ago: all cultures have a concept of a time long ago, at the beginning of things, when “the ancients” lived, etc.
The awareness of some time intervals are essential for survival – nomadic people needed to know the seasons in order to follow migrating animals. Our sense of the passage of time is speculated to be as a result of the interaction of the cerebral cortex, cerebellum and basal ganglia in the brain. Certain time intervals are definitely social constructs, such as the length of a week, the measurement of minutes or seconds, or when one is considered early or late to an event (that differs by culture). Some cultures think of the past as in front of them (before the eye and visible) while the future is behind them (not visible). But our perception of time intervals, both modern and ancient, and their importance to us take on some surprising characteristics.
Numerous experiments have demonstrated that people have the ability to accurately detect the passage of time. One experiment on judging 3 minute intervals showed the difference our age can make in time perception (keep in mind, this is based on seconds and minutes – a definite construct):
- 19 to 24 year old subjects: demonstrated the ability to judge 3 minutes within a 3 second margin of error
- 60-80 year old subjects: tended to consistently judge 3 minutes at around 3 minutes and 40 seconds
There are other examples that seem to warp time. Studies show that we will drive faster to some music, such as “Ride of the Valkyrie” and that fog makes us underestimate driving speeds. And most people reflect that Summers seem longer during childhood.
One example of warped time is the perception that time slows down during a crisis (like a car accident). But an experiment showed that “Time Dilation” doesn’t seem to actually happen. In the experiment subjects were given a special wrist unit which flashed numbers just a bit too fast for a human to see. Then they were dropped from a platform into a net. They were instructed to look at wrist unit as they feel to see if they could read the numbers. Assuming that the brain does slow time during a perceived crisis would mean that the subject could see the numbers – but they could not.
There’s much more to study about the perception of time. For example the effects of emotional states on time perception (temporal illusions), our how drugs or temperature effects our perception. The subject is considerably vaster than can be covered in these notes. One of my favorite reads was an article about The Long Now project, which is working to a construct a timepiece that counts down the next 10,000 years and hopefully help humans rethink our concept of cultural time, and the far, far future.
Perception of time is important in Web development. Studies show that readers are acutely aware of load times. Even a few seconds’ delay for a page’s load time is too long (where the related infrastructure is not robust enough) is enough to create an unpleasant user experience. See Nielsen Normal’s study on Website Response Times.