The Mirror Illusion

The brain is a wonderful organ. It provides us with a mostly accurate representation of the world around us, by making approximations based on sensory input and past experience. This has been mostly sufficient for our ancestors and their environment in which our brains have evolved. There are many examples of how the brain can be fooled, ranging from optical illusions, stereoscopy, to multi-sensory illusions such as virtual hands, phantom acupuncture, and the famous McGurk ba-ga experiment. What I will discuss here is something fundamentally different, which is how your brain can fool you by how it constructs the reality you perceive; and in particular, how difficult it can be to perceive it differently, even if you know the bias.

Look inside a mirror. You will see an image of yourself with a lateral but not vertical inversion, i.e., the left/right seems swapped but not up/down. A watch on your left hand shows up on the image’s right hand, but a shoe does not show up on the image’s head.

Think about it for a minute. That makes absolutely no sense, as the mirror is a piece of reflective glass, and should not discriminate between left/right and up/down. Most people have not thought through this apparent paradox. If you have not, I encourage you to take some time to think about it, and you will find that all of the obvious explanations that come to mind are in fact, incorrect. When first presented with the problem, I found myself experimenting with a mirror, closing one eye, in various orientations, and imagining different scenarios without gravity, to no avail.

What makes this problem so difficult? Simply put, we are looking in the wrong places. We look in the wrong places because what the brain constructs (and what we perceive) feels so real, we take for granted that it is real, and automatically exclude it from closer examination.

The first, and rather difficult step, is to realize that the mirror doesn’t care about direction.  You care about direction, and it is your brain that comes up with the representation, not the mirror. To illustrate this, point to the right, and the image will point in the same direction. Point up, same thing. However, point towards the mirror, and the images points back at you, in the opposite direction. The key observation is that the mirror inverts not in the left/right or up/down, but the front/back direction.

The second step, is to realize what you are actually seeing in the mirror. Imagine a cone pointed towards a wall. As you push the cone into the wall, imagine a cone growing on the other side of the wall, growing as you push, in the opposite direction. You end up with a cone, pointing towards you, on the other side of the wall. Put a red dot on the left side of the cone and a blue dot on the right side of the cone, and do the same thing. An inverted cone emerges on the other side of the wall, with a red dot and a blue dot, on the same corresponding side. Now, imagine a human face being pushed through the wall nose first, just like the cone, with the colored dots as eyes. You end up with an image of a face on the other side, inverted. The left eye is still the left eye, just flipped inside out. Although convoluted and highly counterintuitive, it is the correct interpretation of the image in the mirror.

Still having problems visualizing it? Take a latex glove and put it on your right hand. Now, take off the glove by inverting it, so it is inside out. The inverted right-hand glove is the analog of the image in the mirror, even though it looks like a left-hand glove.

The question now becomes, why do we so instinctively see a person swapped in the left/right direction, to the point where you cannot help but see it that way? The reason, simply put, is that it requires the least work from the brain. The correct interpretation (inverting), requires an incredible amount of work, as evidenced by the effort it takes simply to imagine it. There is no existing brain circuitry to do an inversion, because there was no need to do so when the brain evolved. It is far easier for the brain to represent the image as “someone” facing you rather than an inverted meaningless image. The agent detection circuitry in your brain is where the problem is, not the mirror.

Once the brain treats it as a “person”, it needs to orient the “person” in space to make sense of it. There are two main ways to mentally turn objects around in space; around a vertical axis (turning around), or around a horizontal axis (think foosball). Technically speaking, both ways are equally valid (as are any diagonal axes). Our brain will use the existing evolved circuitry, which is to turn around the vertical axis and spin the “person” around to face you, for that is what it encounters day-to-day. Interestingly enough, if one were to mentally flip around the horizontal axis, foosball-style, one would see the image as up/down inverted but not left/right inverted, further proving that the mirror does not discriminate, and the problem arises from a hardwired preference in your brain.

This example shows that something seemingly so real and right, is no more than an erroneous representation concocted by the brain. The explanation is counterintuitive, but readily verifiable, and probably enough to change your mind. Of course, this is a trivial question with a not so trivial answer, with no vested interest or emotional investment.

It makes me wonder though. I feel quite confident and passionate about many issues, far more complicated and nuanced than a piece of reflective glass. How many of those could I be completely wrong about, simply because it “feels” right? How many wrong trees could I be barking up, blissfully ignorant of the squirrel squarely perched on my back?

I wonder.


Yearning for a Hero

Judgments are clouded by emotion, and nothing brings out emotion like a highly charged event:

On Feb 4, 2015, TransAsia flight 235 ran into trouble shortly after takeoff and plunged into a river, clipping a taxi and bridge in the process. 43 people perished and 15 survived.

In the immediate aftermath of a catastrophe, when emotions are in overdrive, it is human nature to look for anything to lessen the pain, to divert attention, to ameliorate the situation. And what could be better that the ultimate silver lining……a hero. After all, it changes the narrative from an outright tragedy into a tale of a hero fighting to the end.

With reckless abandon, the notoriously salacious Taiwan media pushed the hero angle. In the days following this tragedy, the media and general public praised the pilot for flying along the river, avoiding populated areas, and making it less tragic than it could have been. cuterIn news reports and social media, he was elevated to a saint, a hero, a god. The general public, eager to shift their focus, gobbled the narrative, hook, line, and sinker. Anyone even remotely questioning that status quickly experienced the viciousness that only online anonymity can engender.

Did the pilot really deserve to be called a hero? Let’s take a closer look.

The first point to examine is whether the pilot was at fault to any degree. If pilot error caused the flying tube to inadvertently engage a lakebed, it would take a Stockholm Syndrome-type of twisted logic to call the pilot a hero. It would be like calling a quarterback a hero because he recovered the ball that he fumbled, and caused his team to lose by 10 points instead of 14. By declaring the pilot a hero, however, Taiwan’s media practically precluded the possibility that he was at fault. Evidently, their favorite sport is jumping to conclusions.

The final investigation report is not published yet, but preliminary reports seem to indicate that the pilot might have turned off the wrong engine (apply palm to face). This two engine plane can fly on one engine, but definitely not with none. This is eerily reminiscent of the surgeon who amputated the wrong leg.

For argument’s sake, let’s assume the pilot had no fault whatsoever. The question is, were his actions so extraordinarily courageous and altruistic to qualify him as a hero? Did he go above and beyond what is normally expected or required, and significantly risking personal welfare for the benefit of others?

The pilot seems to have maintained composure in the face of mechanical problems, and flew the plane along a river to minimize collateral damage. Some argue, that alone qualifies him as a hero, as a normal person would not be able to. This is fallacious, as a pilot should not be compared to a layperson. By that logic, a doctor would be a hero for not fainting when he is elbow deep in a patient. And a similar logic applies to prostitutes.

Pilots are trained specifically to handle emergencies; to stay calm first, then aviate, navigate, and communicate. The bar is set high, and we rightfully expect our pilots to meet that standard. Choosing to fly along an open, flat area with emergency landing potential, for example a river, is also a basic part of pilot’s emergency training (see page 2 of this FAA emergency procedure manual). This is a no-brainer; any sane person would choose an open river over a highly populated concrete jungle, with or without pilot training. Calling the pilot a hero simply for not committing mass murder by purposely plunging into buildings, is like calling a bus driver a hero for pulling over rather than intentionally plowing into the opposing lane. It cheapens the word and renders it meaningless.

The last reason is a bit more subtle. In the “trolley problem” moral thought experiment, you see a runaway trolley barreling down the tracks. Tied to the end of the tracks are 5 people, certain to die if no action is taken. There is a lever that can cause the trolley to go down an alternate track, at the end of which lies one person. The moral dilemma is a difficult choice between causing 1 to die through action or 5 to die through inaction.

In this case, the pilot is the decision maker, but in a sad twist, also sitting in the metaphorical trolley. His own life is on the line, which muddies the line between self-preservation and altruism; he is not risking anything more than he already has. In poker, it would be called a freeroll, with everything to gain and nothing additional to lose. I suspect that every reasonable person would do the same out of altruism, if not self-preservation, with few notable exceptions.

To summarize, the pilot cannot be called a hero because:

  1. He was doing his job (nothing extraordinary)
  2. His life was on the line (self-preservation)
  3. He very possibly was significantly at fault (shut off wrong engine)

The love for heroes seems to be universal, as it appears in every culture, and can be explained by evolutionary psychology. Naturally, we yearn for heroes, often with grossly misguided approaches. Genuine altruism touches upon our innermost sense of morality, telling a narrative of fellow beings who voluntarily risk life and limb for others; that perhaps one day, under the right circumstances, we ourselves might be inspired enough to be someone’s hero. It is a compelling narrative indeed.

We would not be human beings if we did not have emotions, and those emotions can be manipulated to affect judgment, sometimes by other parties, sometimes even by ourselves. False narratives provide that very emotional comfort zone, somewhere we can retreat and feel good. Everybody needs a bit of mental masturbation now and then. Just like the real thing, as long as it’s kept private, things won’t get awkward.

I am not trying to minimize the suffering of the victims in this tragedy, which is very real indeed. Looking for a silver lining that isn’t there is like looking for an excuse that doesn’t fit. Both are emotionally appealing but serve no real purpose, because in the end, a false hero provides no comfort, and explanation does not equal exculpation.