THE ILLUSIONS OF TIME, AND HOW WE HAVE BEEN LIVING IN A REALITY AS “INTERPRETED” BY THE BRAIN?

The human brain is high proficient at filling the gaps to make sure that everything becomes meaningful.

We have a really awesome brain. But awesomeness of the brain does not only lie with the processing of individual tasks (cuz that would consume a lot of resources), but with the way how it has prepared in advance lots and lots of algorithms in order respond to various events that may (or may not) happen in the future.

To put it in a nutshell, instead of expending resources to recalculate from scratch the movement of each vehicle on the road, the brain has developed a mechanism to help identify moving objects in space, including vehicles and many other things [1].

Still, despite having so advantageous features that help tremendously with systemization, the brain does have weaknesses, that may allow some of the silliest errors to exist in some very special case. Illusions are some of such errors. However, just like paradoxes in mathematics, cognitive illusions of the brain are extremely rare, and often occur in some rather unusual individual cases. Most of the time, both mathematics and our brain can simultaneously handle a large number of tasks with excellent precision and efficiency.

But, as humans, we always tend to see the correctness of mathematics or our brains as a given, while paradoxes or errors, on the other hand, are seen as something “really out of the ordinary”. Thus, we love to hear story about illusions, as they are chance for us to watch our seemingly-omnipotent brain looks a little dumb and powerless.

1. The excellent-at-predicting brain and the flash-lag effect.

In almost every penalty kick, the goalkeeper would select a certain direction and bet on the shot to go that way, and there has not been a single case where the goalkeeper waited for the penalty taker to kick the ball and then guess where the ball would go to. Because that feat’s simply virtually impossible, as the amount of time necessary for the brain to process all that information would always exceed the amount of time in which the ball would travel from the taker’s feet to the net [2]. But aside from some real-life circumstances that actually unfolds faster than the brain’s processing speed such as the goalkeeper’s defending a penalty kick, for almost every other activity that we do in our life, we do always perform them with a certain level of lag from the brain. However, this latency is often so short that it’s mostly imperceptible in our daily activities.

Let’s say, for example, when you read this text, the light has to travel to the eye (and this process does take a quantifiable amount of time, even though ever slightly so), and then that data is processed to become something meaningful and then finally gets “digested” in the logical cognitive system that was trained to process this information [3]. Thus, regardless of what we perceive, it’s impossible for us to perceive it at the same moment that it happens.

What’s more, the reality discrepancy can also vary based on the body part that receives the information, or the level of complexity of the information. As most data are processed in the brain, and the neural signals from different parts of the body take different amounts of time before they can reach the brain, the responses as directed by the brain would be more delayed at one part of the body than another. For example, when the nose and one of the great toes are simultaneously touched, we would feel like our nose was touched first [4]. As this phenomenon become more commonly experienced by the mass, it has inspired a certain statement of generalization that you may have probably heard cited by many: “We always live in the past, at least 13 miliseconds behind reality (and maybe even longer depends on the type of information) [5].

But, the truth is, things are even more fascinating than that.

The human brain is high proficient at filling the gaps to make sure that everything becomes meaningful: It has the ability to recognize the general rules of reality to perceive what was the missing piece that is needed to fill up the gap between 2 events that share a logical relationship or to predict the future (as well as past) position of an object that has translational trajectory to help form a more seamless and timely picture [6].

For example, in the early days of cinematography, the movies were actually a series on 15 photos consecutively taken within 1 second [7]. Which means the incredibly sophisticated reality of a second, in which perhaps tens or hundreds or even thousands of changes might have happened within each of the milliseconds, were actually represented with just 15 photos — and somehow our brains were completely fine with it. Nowadays, the standard has been raised up 24 frames/sec, and sometimes 60fps for better smoothness (though, at the same time, the high fps actually makes the shot appear a lot more “artificial” to our eyes). But no matter how high technology can bring the fps, it is just undeniable that film shots can never match perfectly with the flow of movements that happened in reality. There will always be something missed.

Even then, this omission of details doesn’t seem to matter anyway, because the most recent researches have revealed that us humans are simply unable to tell apart different levels of smoothness of 60fps and above. Which means there’s an upper limit to how seamless our perception of the world can get [8].

In addition to the ability to automatically fill in what’s not there in order to recreate a seamless “reality”, our brain also knows how to adapt to and predict patterned loss to omit or reinstate. This mechanism can only become perceivable when we test it with many random individual experiments, to see how “blatantly” our brain has tampered with the reality.

One notable example is flash-lag effect [9], where our brain failed to correctly perceive 2 images as our brain “gets ahead of itself” and predict the appearance of either of the two moments, which led to a false perception of reality.

For example, when we watch a hollow circle rotating on a clockwise orbit, every time the circle reaches the 9h position, there will be a red circle appearing exactly at the center of the mentioned hollow circle. Which means every time the circle hit the 9h position, the hollow circle will be filled with the red circle. However, we will end up seeing the red circle appearing later and outside of the hollow circle. In a similar manner, in a experiment when we have a red moving translationally from left -> right, and every time it reach the midpoint, a blue point will appear at that exact moment, and with its vertical axis aligned with the red dot, but our eyes brain will actually perceive the blue dot to appear later than the red dot’s hitting the midpoint.

There exist many explanations for this phenomenon.

The Motion Extrapolation Hypothesis explains that our visual system has made an extrapolation on the trajectory of the hollow circle (or the translationally-moving red dot) to predict their next position in the future. Due to the processing lag that we’ve mentioned early in this article, if without this extrapolation mechanism, by the time we perceive the red dot to reach point A, in reality it would have passed point A by a bit. As a result, visual mechanisms will try to account for that latency by analyzing and extrapolating for the real-time position of the object [10].

Another hypothesis — the Latency Difference Hypothesis — proposes that as the brain is better at processing the movement than the blinking of an object, and thus the two realities that appear at the same time might actually have been perceived with different latency [11].

The Motion integration and Postdiction Hypothesis, on the other hand, explains that when we are receiving stimulus A, and then receive another stimulus B, the process of analyzing stimulus A might be interrupted or warped [12]. As a result, the appearance of the light dot (B) has caused the brain’s perception of the hollow circle’s movement (A) to get warped. Later, people had integrated this hypothesis with the Motion Extrapolation Hypothesis, saying that after the information processing on the hollow circle’s movement got interrupted by the appearance of the red circle, the visual system had done some extrapolation to account for the missing information on the hollow circle, and put it back to the right place on its trajectory (which is of course is no longer overlapped with the red circle, cuz the perception of the red circle of course would have already happened), and thus cause the flash-lag phenomenon [13].

2. The brain also calculates “time” for itself (The Kappa effect)

As the reality we perceive is made up of lots and lots of latencies, omissions and extrapolations, our perception of time also constantly gets warped, depending on the way the brain processes it. A 15-minute may seem like forever sometimes, while some other times a few hours might just pass in a blink of an eye, and ever so literally.

We actually once had an article where we discussed the time in physics (we will provide the link to this article in the comment section below) [14]. Specifically, while time can be dilated as a result of Einstein’s Theory of Special Relativity, it is actually fundamentally constant in relation to the changes of reality. For example, a second is defined as a half-life of a radioactive element (for further details, please read the article on the link №14). So therefore, in some aspects, 1 second is still 1 second.

As for the perception of time, it is, by definition, something that is created by our cognitive system and, thus, is prone to errors and illusions. Sometimes 1 second may feel longer than another second.

The most canonical example for this is the Kappa effect, also known as the “perceptual time dilation”, is a temporal perceptual illusion that can arise when observers judge the elapsed time between sensory stimuli applied sequentially at different locations [15].

For example, supposed there are 3 light bulbs that are attached to the 3 points A, B and C. The distance from A to B is farther than that from B to C. With these 3 light bulbs blinking constantly with equal interval (for example, light bulb A is turned on and off, and then light bulb B is turned on and off, and after that light bulb C is turned on and off; each blinking process takes the exact same amount of time). Here, while in reality the blinking intervals between the light bulbs are exactly the same, the observers will perceive the interval between the light bulbs A and B to be longer than that between the light bulbs B and C.

For a good explanation for this phenomenon, you can refer to the Constant Velocity Expectation hypothesis. According to which, our brain has automatically considered the blinking process of the light bulbs as an uniform motion with constant velocity, and as the intervals between the light bulbs are different, the time duration of such motion would somehow become… different (based on the simple formula: Time = distance/velocity) [16]. This built-in algorithm is highly useful in most cases, but also becomes a loophole for errors in some special cases.

What’s even more fascinating, the Kappa effect can actually vary depending on how the experiment is designed. For example, the faster the blinking processes take place, the more clearly perceptible this effect will become. Another example is when the light bulbs are arranged in a vertical line, the effects will be stronger if the light bulbs A to C are arranged in a top-to-bottom order instead of the other way around (this might have stemmed from the expectation of a downward acceleration in complement with gravity) [17].

However, the brain doesn’t stop at giving predictions with great accuracy based on the laws of physics, it also eliminates unfavorable factors to help the processing of information to take place more smoothly and with better resource efficiency.

For example, for insignificant but latencies that are frequently repeated, the brain would just ignore them after getting accustomed to them and will interpret it as if the two intermittent events actually happened simultaneously. For example, in an experiment where the participants were asked to press the button to turn on a red light, with a latency of around 80ms (which meant only a short bit after the button was pressed would the light begin to glow); and the result was that after a period of getting accustomed to the latency, the participants would feel like the light lit up immediately after they pressed the button, and would no longer perceive the said 80ms latency.

The interesting thing is that, when the latency was later reduced to 40ms, the participants actually felt like the light lit up before they even pressed the switch [18]. The same phenomenon was also observed in a similarly-designed experiment but with the stimuli being the movements of the computer mouse and the cursor when the participants are asked to play video games: After getting accustomed to the latency A, the participants started to feel like the cursor moved before they moved the mouse when the latency was reduced to A’ [19].

So, somehow, the seemingly omnipotent entity that is our brain, with all of its godly ingenious and sophisticated mechanisms, had led itself to a conclusion “so wrong it couldn’t get any wronger”, as it told us that the light lit up before the button was pressed even when it was the body that it controlled that pressed the button (and even when the light by logic would never light up, had the body not pressed the button).

Even in the context of such simple logic, our brain still got confused. So is there any limit to how much our brain can trick us?

Beyond the typical illusions, there are lots and lots of the more subtle and yet virtually omnipresent illusions that always affect our perception of reality.

Karl von Vierordt, a German psychologist, was ahead of his time as he discovered this scientific law that was later named after him, which proposes that when performing estimations, humans tend to overestimate shorter periods of time, and underestimate longer periods of time [20]. For example, when we attempt to recall the past or imagine the future, we often see “10 years” as not nearly as long as it should physically be, while “1 hour” would often feel longer than it should be in reality. Moreover, we are not also not very good at comparing two different quantities estimated by our brain, like for example comparing the estimated 1 hour and 10 years.

Another good example of this would be Chronostasis illusion, a kind of time perception illusion, in which the first impression would cause us to feel like things take longer than they really do [21]. For example, when we look at the clock’s second hand, we would see it standing still for longer than it actually does; or when we call other, when the dial tone’s running, if we put the phone down for a bit then pick it back up to listen again, we will feel like the beeping has become so long that it gets us impatient.

The reason for this is, our brain has automatically “inserted” the image of the second hand before we turn our eyes to the clock, and thus the data on the hand’s standing still lasts longer than in reality. But the question is, why does our brain have to perform this data insertion?

It’s because when human eyes move from an object A -> object B, while the received image is supposed to subject to motion blur like how it is when we swing the camera, our brain was actually incapable of receiving this form of information, and thus, it would just replace those “blurry” section with the data it received immediately after that, which, in this case, is object B.

The phenomenon can be summarized in this following model:

Visual system: A -> blur -> B.

Cognitive system: A -> B -> B.

And thus, “A -> blur -> the second hand” was interpreted into “A -> the second hand -> the second hand”.

This process of processing blurred information happens constantly, but in the case of the clock’s second hand, the perception of the 2nd second and all the seconds after that were normal, unlike that of the first second which were “inserted” with some data, and thus we always feel like the first second last longer than any other second after it.

3. “The reality”.

And thus it is pretty much evident that the world that we perceived is (and will never be) perfectly matching with the real world (if there really exists a “real world”). The processes that take place during our brain’s processing of reality such as extrapolation, insertion, omission, … for reality to be perceivable … would every now and then cause discrepancies, though these are by no means significant.

However, as all of us do own brains that are similar in structure, and that employ the exact same mechanisms, the reality that we perceive would be almost “perfectly” the same. So even when we never end up living in the same world, we can still together discuss it using an universal system of language and consensus. For example, even if not everyone is seeing the same red color, a definition of “the color red” will help one person to explain to another what they are trying to describe in “his own world”.

There exist many medical conditions that can tamper with different information processing mechanisms of the brain, like, for example, mental conditions, which can disrupt the communication of the its victims with other people in the society. Or in case of substance use, the phenomena of hallucination and illusion are also the results of the chemical substance’s tampering with the normal functionality of the brain. We will elaborate further on this topic in our upcoming articles.

But what needs to be noted here is, any kind of debate or contemplation over “reality”, if introduced, needs scientific and, in addition, even philosophical basis. Because when our brain cannot reflect 100% of reality as it is, It doesn’t mean that human cognition is not reliable.

And it also doesn’t mean that any of the novel tools and means that are products of the said cognition are worthless in helping us gain and better and better understanding of objective reality.

Just like with the illusions and hallucinations mentioned in this article, isn’t it just us (and not a Lord of Creation) that has taught ourselves to become fully able to perceive ourselves by the means of science — which is also another product of our cognition?

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References:

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