In the past two chapters you have hopefully become a little doubtful about your own interpretation of the world. Often we cannot fully trust our own ideas about consciousness, or we do not have the right tools to substantiate it.

It can be pretty scary to realize that you cannot trust your own experiences, and if you go too deep it can throw you in a deep dark hole. However, it can also feel very liberating for some.

The point is, sometimes the existence of consciousness can seem like an illusion. Remember that an illusion does not mean that there is nothing - an illusion means that there is something that seems something else. (Example: a barking dog is an illusion of aggressiveness - however, it is not aggressive but scared.)

In the context of consciousness, it is important not to forget this definition. When we say the consciousness is but an illusion, we mean to say that in fact, it is something else that hasn’t been explained yet.

A good example of illusions are the visual ‘optical illusions’ that we all know. Our brain create an image that isn’t actually there, but that doesn’t mean there is nothing. What is there are the things that create the illusion, and our brain makes something else out of it.

Vision, can be argued, is our primary sense. If two senses are competing (such as seeing someone say something and hearing something else) – vision wins most of the time. Our language is littered with visual allegories too, such as ‘I see what you mean’.

That doesn’t mean that vision is never wrong, however – cue the optical illusions. Just like our thoughts and experience, vision can sometimes betray us and show us something that isn’t there, or leave out something that is.

Can we go back to the beginning?

It’s hard to imagine not seeing if you have seen all your life. It’s such a basic thing that, just like breathing, you are not consciously aware of doing it most of the time. But now try to focus on seeing. Look around, close your eyes and open them again. Do you see one picture? Do you see loose elements combined into one? Do you see everything or just a little bit at a time? Do you notice anything you didn’t see before?

It’s weird how these questions focus your awareness, huh? This oddity is what caused the term ‘grand illusion’ to arise. Vision can be seen as just an illusion, and here’s why.

There are three theories to our vision. 1) There is a large amount of visual experiences all needing to be explained at the same time, 2) there is a difference in what we see and are aware of, and all that we’re not and 3) seeing is like having pictures in your head.

The first one is pretty simple. There is a constant input of things that you see that your brain needs to explain or context. This can cause discrepancies. (Exercise 1)

The second one is relatively easy too. Think of a theatre: the things on stage are what you are aware of, but you cannot see what is behind the curtain. Thus you are not aware of it. This exactly the same as the things happening outside your visual field.

The third one is trickier – simply because it is highly debated and not proven in the slightest. You see, (hehe) the theory says that the world is represented in your head, almost like a movie. Which, fair enough, is easy to believe because you see the world in images, do you not? But the thing is, close your eyes and imagine something. Do you see it in a picture? Words? Some odd combination of the two? Or is it just a thought, made of an entirely different substance?

The idea of seeing and imagining things in pictures stems all the way back to the Ancient Greeks. People like DaVinci argued the eye was like a reflection in a dark chamber. In the 17^th century, Kepler studied the eye’s optics and Descartes continued this work to find out how the eye functioned. At the time, his work was overlooked entirely, but now that we know more about the functioning of the eye, the pictorial representation seems entirely plausible. The question remains however, if what we imagine are actually really pictures.

The problem with taking all these three assumptions and combining them together is that we are still stuck having to explain how all the neural pathways work, which then also leads back to the ‘hard problem’ of this book. How and where does awareness arise?

Why are there gaps in your mind?

William James was the first to address something we all notice from time to time; gaps in what you see. Have you ever had that you never noticed something was there, but now that you have, you cannot help be always see it?

It’s strange to think about that you never saw it before, but that there wasn’t some sort of gap in your vision. You just saw nothing out of the ordinary. Is it because it seems that your mind fills up the gap with some other sort of information? If your brain knows what is there though, does it need to fill the space up with something incorrect?

If you see a car parked behind a tree, you don’t see two part of a car, you see one single vehicle, so obviously your brain fills some stuff in, even if it has no idea what is behind the tree (object permanence). Maybe it’s just an automisation of the brain. After all, we have a blind spot in our eye, so our brain is constantly filling up a gap anyways.

It would be easy to argue this if you’re constantly in a room with the same images pasted all over the wall. After with a quick scan you’ve identified that they’re all the same, you can focus on one and know all the others – noticing errors quicker too. But on a busy street where you’ve never been before, your brain somehow seems to manage too. So how?

It seems that our brain takes cues from the environment in blind sports, combines it with experiences and knowledge and thus creates a plausible fill of the blind gap. This is how a full, uninterrupted visual field is created. This also explains why the filling up is sometimes incredibly wrong.

Sometimes, it seems though, it takes more time for the brain to fill up. Experiments have show it sometimes takes up to five seconds for the brain to fill in the gaps and, for instance, connect two lines with each other. This proves that the brain doesn’t neglect the fact that there is information missing, but responds with various speeds.

What is change blindness?

How much do you think you are actually aware of in the world around you? Would you notice if the baseball cap of the guy sitting a little sideways to you suddenly turned from red to purple? Probably not.

This is because, even though we think we see everything, you are always focussing on one thing at a time. Everything else we see (saccades) our brain deems unimportant. So if one of these saccades change, we probably do not notice because again – unimportant.

Change blindness can be tested by showing several images in flickers or with blanks between them. This forces the brain to constantly focus and thus miss out on information, resulting in change blindness. You we refocus on the same thing as before, thus missing out on changed information.

It mostly, as I said before, has to do with attention, and where we focus it. But funnily enough, even the most obvious or noticeable features of an image can be prey to change blindness – such as a white person turning black, or vice versa.

What is inattentional blindness?

 Yes, this is different from change blindness.

Do we really see something if we don’t pay attention to it? When first in a new space, we tend to sweep our attention around the room, but if you come into a place you’ve been a thousand times before, would you notice a new lamp hanging from the ceiling?

When we don’t pay attention to something, we tend to not see it at all. Go to YouTube and google inattentional blindness video’s. I bet that, even after just reading this summary, you’ll still miss whatever they’ve got sweeping around in the video you chose.

Inattentional blindness can be particularly dangerous. NASA tested it with a simulated plane landing and an obstruction they placed on the landing lane that they never placed there before. Novices that did the simulation for the first time tended to notice the obstruction straight away, while experienced flyers sometimes didn’t see it at all. The same can happen while driving a car on a road you’ve been on a thousand times before. Would you suddenly notice a dog on the road if you weren’t expecting it? Or if you’re walking on the street while calling on the phone, having a heated conversation, would you notice a unicycling clown pass by you? You would like to say yes, but studies show that this is often not the case.

What are the implications?

Things such as change and inattentional blindness challenge the previously laid theories. If the world is built up in your head from the things that you see, how can you not notice these things? If the world is perfectly mirrored through your eyes, you should see these things, and therefore notice then.

A new theory formed out of this knowledge is that, if we see two images quickly after each other, we get the gist of the picture from the first image. If then, with the second picture, the gist is the same, the brain spares itself the effort and just ignores the changes as unimportant. We see multiple things at the same time because our brain fills up the things outside our direct attention with the gist information of that object, combined with logic and past experience. These objects are thus neither stable nor detailed. For that, we need to direct our attention to it.

Another theory is that we are constantly manipulating what we see, and thus are interacting with the world – which in turn makes so we can see. It we stop manipulating, stop interacting, the world will disappear into nothingness. Now, to me, this seems like an illogical circle, but hey, that is just me.

O’Regan and Noë had an experiment where they let a perticipent, let’s call him Simon, see a cup on the table in front of him. If our brain could build a proper representation, then with his eyes closed, he would be able to reach for the cup perfectly. (Exercise 2) Now with glasses that disjointed his vision, he was asked to do the same. This required much more effort, because he had to align his physical awareness with what he was seeing, just adjusting his motions away from what he vision was telling him.

Exercises

3.1. Next time you’re sitting at a computer and look down while typing (as I am now), try and become aware of every movement your fingers make. Do you consciously see your fingers hitting each key? Or does it go too fast for your eyes and brain to keep up with. Notice that, as soon as you start consciously seeing your fingers come down, you will suddenly make more mistakes. Weird, huh?

3.2. Try the Simon experiment for yourself! Close your eyes and reach for something on the table.