“Time is related to the rate of change experienced by our minds”
And, our sense of time affects our mood. If your brain perceives time moving slowly, you will feel that time is dragging and will become impatient and impulsive. You might start missing deadlines or underestimating the time needed to reach appointments. You might cook a dish for 15 minutes instead of the 10 minutes the recipe required. We all have a sense of time that varies in accuracy depending on internal and external factors. A typical example is waiting at a traffic light. When the light turns green, your internal clock starts ticking. Based on your past experience, you do not wait for the orange light to engage the gear and go. Your sense of time tells you when you have to do that without any external cues. We all experience time differently, each in his own unique way, and that experience starts with the perception of the present, that moment in time we call now.
The Illusive “Now”
We see, hear, feel, and think “now.” What is experienced is experienced in the present moment. It is a moment in time between a “no more” and a “not yet.” You might think that a “now” moment is instantaneous, having no duration, but it is not. If it was, we would not feel any continuity in the flow of time. Psychologists define the duration of a present “experienced moment” as just about the longest time interval we can perceive as a whole and still call “now.” When we experience the flow of time, we do it through an event that is first anticipated, then experienced, and eventually remembered. For instance, when you hear a word in a spoken sentence, you can only understand it in relation to the preceding and succeeding words in the language structure. Likewise, when you are listening to the melody in a song, the “experienced moment” corresponds to what is presently in your mind, including the note played just before and possibly the note expected to follow immediately after. If you are familiar with the Beatles song “Hey Jude,” for instance, the moment you hear “Hey,” you cannot help but hear “Jude.” The “Jude” is somehow present in your mind even though it is still anticipated in reality. Likewise, when you hear “Jude,” the “Hey” is still somehow present in your memory, even though it is no longer sensed. 5 This “experienced moment” involves both anticipation and memory. What we experience as the present “now” is strongly interwoven with what has just happened before and what is about to happen. 6 This integration of past, present, and future within an “experienced moment” is what maintains our sense of time continuity and it provides the basis of our consciousness and subjective present. They are the fundamental elements that compose the train of our thoughts. So how long is an “experienced moment”? What is the duration of a present “now”?
In 1868, German physiologist Karl von Vierordt became interested in people’s ability to guess time intervals. He observed that people tend to overestimate short intervals and underestimate long intervals. It implied that there must be an interim period, whose duration people could guess correctly. This is called Vierordt’s Law. Vierordt found that this indifference interval was around three seconds. It is as if the 3-second interval was related to an intrinsic property of our brain that makes it easy to guess accurately. 7 Could this be the duration of our experienced “now” moment? Another clue comes from optical illusions.
If you have ever seen optical illusions such as Rubin’s Vase/Face, the Necker Cube, or Boring’s Old Woman/Young Woman Illusion (online examples are easy to find), you may have noticed that these ambiguous figures are static images that have two distinct interpretations. During prolonged viewing, the image in each illusion changes its appearance to the alternative interpretation in a sudden and unavoidable mental switch. A few seconds later, the brain switches back to the original interpretation and the alternation continues regardless of how hard you try to hold to one interpretation over the other. Brain scientists have discovered that the time between mental switches depends on several factors and is, on average, around three seconds long. The brain’s neural circuitry defines the mental switch period and determines its duration. This is similar to a computer screen’s refresh rate. The brain’s refresh rate seems to be three seconds long. Every three seconds our brain asks “what is new?” and our sense of “now” is updated.
Yet another clue for the duration of an experienced moment comes from short-term memory. Short-term memory is a mental system that stores temporary information for immediate use and manipulation. Our short-term memory capacity is defined as the amount of information we can hold in our minds without losing it in the presence of other information or distractions. Scientists have estimated that information is normally stored in short-term memory for two to five seconds. 8 Afterwards, if the information is not needed, it is forgotten or else it is stored in our permanent long-term memory. Of course, this varies from one person to another. Some people have the ability to hold several items in their short-term memory while solving a problem or performing a distracting task and others can barely remember a sequence of three numbers. The capacity of our short-term memory determines our overall span of attention, which in turn sets a limit on the duration of our experienced moments that make up the present “now.”
In a seminal paper, the eminent French experimental psychologist Paul Fraisse summarized the experimental findings of the last few decades and concluded that the present “experienced moment” is a duration that can hardly extend beyond five seconds, with an average value of two to three seconds. 8 If someone verbally told you his ten-digit phone number and asked you to dial it, you would most likely be able to if you managed to do it within three seconds. Likewise, if you clap your hands three times, with about one second between each clap, when the third clap takes place, are you still directly aware of the first? Most likely not. That first clap will feel that it is already in the past and not part of the present “now.” If, on the other hand, your claps were half a second apart, all three claps would feel part of one present moment. Further evidence comes from sensorimotor control. In a typical experiment, a person is requested to synchronize a regular sequence of sound beeps with his finger taps. This kind of sensorimotor synchronization can only be reasonably accurate when the sound beeps are not more than three seconds apart. If the next sound beep lies too far in the future, say five seconds, it would not be possible to accurately anticipate the finger taps. 9
Therefore, it is not by chance that the three-second interval happens to show up in many areas of our lives. In songs and classical music, musical phrases blend nicely when they are made of musical motifs that are two to three seconds long. The famous musical motif in Beethoven’s Fifth Symphony, the one that sounds like fate is knocking on your door, is around three seconds long. The same is true for poetry: the average duration of a spoken verse in most languages corresponds to about three seconds. This seems to be a universal phenomenon. Try that with any of Shakespeare’s famous sonnets, ‘Shall I compare thee to a summer’s day?” Time yourself as you read it aloud and you will find it takes around three seconds. Radio stations use three-second stings as breaks in a radio program. The soothing sound you hear at the startup of a Windows or Apple computer is three seconds long. Relaxation breathing takes about three seconds. In most cultures, a handshake lasts about three seconds. A hug also lasts for around the same duration.
Psychologist Dr. Emese Nagy measured the duration of hugs while watching the Beijing Summer Olympics on television. Using video recordings of the event, she analyzed the duration of hugs between athletes from 32 nations in 21 sports. Whether it was with a coach, teammate, or rival, and regardless of gender, the hugs lasted on average about three seconds. 10 Similar cross-cultural studies have also shown that goodbye waves also last on average about three seconds. We seem to go through life experiencing the present in a series of three-second windows that roll on relentlessly as they bind the past with the future. And this brings us to the next point. How do we think about the past and future?
“We seem to go through life experiencing the present in a series of three-second windows”
Our awareness of time in the past and future starts early in life and comes in two forms: as a cycle and as a line. As we grow up, we slowly develop consciousness of the world in the cyclical pace of seconds, minutes, hours, days and years. The school bell rings every hour, supper is served every evening, sunrises and sunsets recur each day, the seasons take turns, birthdays repeat every year. Time is perceived as a set of cycles which form the basis of our ability to predict the future. Yet we also know that time is linear; it starts with a beginning in birth and an ending in death.
In our mind, we place important life events on a timeline. If you speak a language that is written from left to right, such as English or French, you will tend to think of the past as something to the left while the future as something to the right. Most English speakers plot timelines from left to right. On the other hand, people whose native languages are Arabic or Hebrew, plot timelines are the other way around. Because these languages are written from right to left, they tend to think of the past as something on the right and the future as something on the left. Since Mandarin is written vertically, the Chinese think of the future as something that is below! Interestingly, bilingual people tend to place the past and future in either position, depending on what dominant language is used in formulating their thoughts.
Our sense of time is a fabrication of our brain to make sense of the events in our world. Since it is not a material object of the world, our brains cannot comprehend time without using physical notions such as distance and space. In English, for example, we talk about a “long” vacation or a “short” movie. We say Christmas is fast “approaching,” the deadline is “near,” or the weekend is still “far” off. We look “forward” to meeting someone or putting the past “behind” us. We cannot think of time without thinking of space and distance, which is a further indication that time itself is not a property of the empirical world.
One significant aspect of this space-time relationship is the fact that the brain perceives the “motion” of temporal events in the same way it perceives the motion of physical objects. Consider, for example, these two sentences: (a) I moved my car forward two meters or (b) I moved the 3:00 p.m. meeting forward two hours. The car in the first sentence is a physical object that can travel through space and whose motion we can easily perceive. By contrast, there is no way we can experience the meeting’s “motion” through time using our senses. We just have to imagine it “moving forward” in an abstract way. For some of us, this means the meeting is now at 5:00 p.m., while for others the meeting is now at 1:00 p.m. Both are equally correct and valid interpretations. It all depends on how you look at yourself in relation to time, or your “time perspective.” You could see yourself standing still while the future moves towards you like a flowing river, from the future to the past. This is known as the time-moving metaphor. Examples of that are “the deadline is fast approaching,” or “I cannot wait for my birthday to arrive.” Alternatively, you could see yourself moving in a straight line towards the future, as if on a conveyor belt, through fixed time. This is known as the ego-moving metaphor. Examples of that might be, “We are approaching the end of the month,” or “we are falling behind schedule.” Since we naturally seek good things and avoid bad things, we have a tendency to adopt one of these time perspectives depending on whether the approaching future event is something that we are looking forward to (ego-moving) or something that we are shying away from (time-moving metaphor). More on that in a later chapter, when we explore how we experience the future.
Half of the World Disappeared
Additional intriguing evidence for the mental space-time relationship comes from people who have trouble comprehending time due to certain head injuries that have affected their understanding of space. One such condition is called Left Hemispatial Neglect (LHN), which causes people to ignore the left side of nearly everything. A number of strange symptoms can arise from such a condition. A man with LHN may only shave the right half of his face, or a woman may only apply make-up to her right side. The left side of things do not exist in their mind. Patients with LHN do not see much of their left surroundings. They often bump into walls to their left, or leave the left half of the food on their plate.
To understand how space is connected with time, psychologist Lera Boroditsky of the University of California in San Diego led a study with French LHN patients. French is written from left to right so, on a timeline, French people tend to put past events on the left and future events on the right. A group of seven French patients with LHN and a group of seven healthy people were told the story of a fictitious 40-year-old man named David. The story involved events that happened to David ten years in the past, when he was 30 years old, and other events that will happen to him ten years into the future, when he will be 50 years old. They were asked to remember as many events about David as they could and to specify whether they occurred in his past or future. The researchers found that the patients with LHN had trouble remembering the events from the past, but could easily remember the events related to the future. The results indicated that in the same way that LHN affects the left side of the space around patients, it also affected the left side of their mental time chronology, which is normally associated with the past. 11 If the same study was conducted with LHN patients whose native language was Arabic or Hebrew, it would follow that they would have problems recalling future events. When one's internal understanding of space is damaged, the sequence of time events and their perception of the future and past is disrupted.
Another indication of how time, space, and language are interrelated comes from languages like Chinese Mandarin, which is written vertically from top to bottom. In English, we look forward to the good times ahead or think back to the struggles of the past and are grateful that they are behind us. In Mandarin, most of the words used to describe that same sentence are vertical in nature, i.e. related to up and down. If you were to show a group of Chinese people an array of horizontal objects and then ask them what comes earlier, March or April, they will respond more slowly than if they had just seen a stack of vertical objects. 12 The converse is true for English speakers. Their answer will be slower if they have just seen a stack of vertical objects prior to the question being asked. When the brain is primed to think vertically, it will require more effort to focus on horizontal concepts such as time, which explains why the responses are slower. Spatial representations that depend on our culture and language are essential to the way we think about time.
Time Estimation: Prospective vs. Retrospective
One more thing to mention here is the way we estimate time intervals. Psychologists found that when people are engaged in an activity and are later asked how much time passed, they will give a very different estimate than if they were intentionally aware of the passing time. As an example, let us say that you just finished watching an episode of your favorite TV show and were unaware of the passing time. Your time estimate is retrospective, because you judged the time interval after the fact, relying purely on your memory of what has already occurred. In that case, your estimate will depend on the number and intensity of the memorable moments you are able to recall. In contrast, imagine you are waiting for the next train to arrive. You know the train arrives in about 10 minutes, but without a wristwatch you try to guess when those 10 minutes will be over. You are consciously aware of the passing time and your estimate of when that interval elapses depends more on the amount of attention you devote to tracking the present time rather than the memory of what has already occurred. Your time estimate is prospective, and psychologists refer to this as the experience of “time-in-passing.” It is important to distinguish between these two types of time judgments because they rely on different brain mechanisms and, as we shall see in subsequent chapters, they produce various time distortions with conflicting time experiences.
Recap
In brief, time and space are intricately intertwined in our minds
. Our concepts of space, distance, and motion shape the way we experience the receding past and approaching future. Keep that in mind because, as we shall see later, this relationship can explain many aspects of the psychological time distortions that we experience every day.
As for our experience of the present, we saw that the longest time interval that can be perceived by our brain and still be called “now” is about three seconds long. To slow down time and make the most of it, our aim should be to make our “now” moments last longer. This would be useful in moments of bliss that we wish to extend. In situations where we need time to pass faster, such as moments of pain, we need to make our “now” moments shorter. The key question, therefore, is what factors can stretch or shrink a “now” moment so we can control the perceived speed of time? To answer that, we need to understand what “now” is made up of and the brain mechanism that sets its duration. We will then cover what factors affect those brain mechanisms and explore ways that can expand or shrink our present “now.”
In the next chapter, we will take a look at the rudimentary inner workings of our brain in order to understand the basic brain mechanisms responsible for perceiving reality. In the chapter following that, we will see how the speed at which we perceive reality defines the speed of time in our mind. We will then look at how psychologists have used what they know about time perception to create a simple internal clock model that we can use to explain how fast we experience the passage of time. This will then conclude the first part of the book and lay the foundations for understanding the various factors that affect the perceived speed of time, which we will cover in the second part, and how best to manipulate those to our advantage. For now, let us continue our journey into the depths of our brains.
The Power of Time Perception Page 3