The following discussion is based on information that can be found fully described in Alva Noe’s book, Out of Our Heads: Why You Are Not Your Brain and Other Lessons from the Biology of Consciousness and Alva Noe’s article from 2002, Is the Visual World a Grand Illusion? I urge you to read both of these, but no worries if you choose not to, as I’ve read them for you and recount what I have learned below.

This post continues the topic I began in “Alva Noe’s Philosophical Concepts 5: Can I believe my lying eyes?”. The issue I am currently focusing on here is referred to in philosophical circles as “The Grand Illusion.” In a nutshell, this is a rather descriptive term used by Alva Noe and others, to explain the current accepted scientific explanation as to how our vision works i.e., that our brains essentially reproduce what our eyes see, meaning that we never really “see” what is out there directly. We’re always at least one-step away from reality. This is also known as “representational perception,” or even “reconstructionist perception,” which believes that vision is really a process of our brains reconstructing the world “out there” and presenting to our brains, based on information encoded on our retinas.

This is more than an academic exercise for Alva Noe, me, or anyone else truly interested in finding out everything we can about consciousness. Why? Well, one reason is because perception is critical to consciousness since without some kind of perception, consciousness doesn’t happen. Another reason is that even if representational perception is accurate, it still doesn’t explain how we see anything! According to Alva Noe, this orthodox theory of perception is just wrong and adherence to this view of perception has led research astray and is preventing progress in the field.

As for me, I would add one additional reason – because I find the topic fascinating!

Do We Really See What We Think We See?

Noe tells us that recent work in perceptual psychology presents a challenge to orthodoxy by questioning whether we really enjoy the “…richly detailed, snapshot-like visual experiences we think we do.”[i] He calls this the “new skepticism.” Essentially, for these new skeptics, the question is not “…how do we see so much on the basis of so little? It is, rather, why does it seem to us as if we see so much when in fact we see so little?”[ii] You may need to read this last quote more than once to get the true gist of what he is saying. I know I did.

According to Noe, one of the biggest proponents of this new skepticism is philosopher Daniel Dennett. For example, in response to a comment made by neuroscientist Gerald Edelman, who had written, “One of the most striking things about consciousness is its continuity.” (1989, p. 119), Dennett responded strongly by saying. “This is utterly wrong. One of the most striking features about consciousness is its discontinuity — as revealed in the blind spot, and saccadic gaps, to take the simplest examples. The discontinuity of consciousness is striking because of the apparent continuity of consciousness.”[iii] (I explain the blind spot and saccadic gaps below).

Alva Noe says, and I have to agree, that this statement by Dennet is “wonderful.” Because it makes it clear that the concern here is not just about perception per se, but about consciousness itself and the nature of our experience. According to Dennett, we are actually “…misled as to the true nature of consciousness.” Consciousness, according to Dennett, is not really continuous at all. It is discontinuous. Yet, it appears to us as continuous. Noe puts this into a rather delightful paradox: “…it turns out that we are mistaken in our assessment of how things seem to us to be.” Think about that for a minute.

Noe then goes through several examples of demonstrations that reflect the new skepticism, that experiences are not what they seem to be. The first is the blind spot demonstration. You have probably heard of it before.

The Blind Spot Demonstration: Each retina has a place on it where there are no photoreceptors, or a “blind spot.” We are typically unaware of the blind spot. What falls on the blind spot in one eye doesn’t fall on the blind spot of the other eye and besides our eyes are always constantly moving, so what falls on the blind spot now doesn’t fall on it a moment later. Yet, we never experience a hole in our vision. It takes “special care” to make someone aware of the blind spot. If you want to see evidence of this blind spot in our vision, you can watch a Youtube video about it here.

Noe tells us that this type of demonstration is often cited as evidence that our brains “fill in” this blind spot, i.e., “the gap in our internal representation of the visual field.”[iv] He asks us, “How else can you explain the phenomenon?” Well, according to Daniel Dennett, this is wrong. He says that our brains don’t fill in the blind spot, instead our brains ignore it completely. He concludes essentially, that “…we are victims of an illusion about the character of our own consciousness.”[v] In other words, Dennett believes that our brains don’t fill in the hole in our perception, the hole is there, our consciousness just ignores it, leaving him to wonder why our consciousness appears to be continuous when in fact, it has these perceptual gaps, which is to say that “…We are the victims of an illusion of visual consciousness.”[vi]

Here, Daniel Dennett’s comments take us down a bit of a rabbit hole (hang in there, it’s important) and we have to ask, as Noe does, whether this particular skeptical reasoning is really valid? Yes, we know our eyes have blind spots. Yes, we know that we don’t really see those blind spots. But is this due to our brains filling in the blind spots? Dennett agrees with Noe, that no, this is not the case. Our brains don’t fill anything in. But is Dennett right to conclude that our consciousness just skips over the blind spots, meaning our consciousness is not continuous, thus leaving us with a whole new problem to noodle over – How is it that our discontinuous consciousness gets a clear and entire picture of the world in front of us? Noe says no, this isn’t right either.

Sure, Noe agrees, we do not see gaps in our visual field, but Dennett’s claim is off the mark. He uses a wall in the house as an example to make his point. If we stand in front of the wall and look at it, we see and experience “…a gap-free expanse of the wall.”[vii] But, explains Noe, this is not the same as saying that we see “…the whole of the wall’s surface.”[viii] In other words, it certainly seems as if the entire wall is there, but “…not as if every part of the wall’s surface is represented in your consciousness at once.”[ix] Instead, what we experience when we look at the wall is that the wall is present before us and that we have access to it by simply looking here, or there, focusing on that nail hole and then another, etc. Noe tells us, correctly I believe, that it is never a part of our ordinary human experience “…that we experience the whole wall, every bit of it, in consciousness.”[x] I would add here to the end of this last quote, “…all at once,” as I think that makes the point more clear.

While the blind spot discussed above is something you may or not have been aware of, next is a phenomenon that we can all relate to.

Change or Inattention Blindness: As children (or even adults), who hasn’t played a trick on a sibling or friend at lunch or dinner by telling them to “Look over there!” and then stealing one of their French fries? When they turn back they don’t notice that one of their fries is missing. All they notice is your shit-eating grin. Alva Noe uses this example (the “shit-eating grin” comment is mine) and tells us that this is because they didn’t notice the exact number of fries they originally had on their plate and they weren’t paying attention to you grabbing the fry. Their attention was directed elsewhere. For an example of this, look here.

So, believe it or not, change blindness is actually a thing and has been researched by a number of scientists.[xi] Apparently the inability to notice change is “…a pervasive feature of our visual lives.”[xii] That’s not to say that we don’t see changes. We see lots of changes, usually because something in our perceptual view flickers or is modified in some way. But if we are prevented from noticing the flicker, say because other things are flickering at the same time, or our attention is turned elsewhere, then we don’t notice the change. What the research has found though, is that we often don’t even notice changes that are happening in full view, changes that are happening right as we are looking at them. This has been verified by experiments done with eye trackers.[xiii]

Change (or inattention) blindness is important to understand because it has, according to Noe, several different consequences. Personally, I prefer to think of these as several different conclusions that can be drawn as a result, rather than consequences.

The first conclusion is that our perception is “attention-dependent.” In other words, we only see what we attend to. If something occurs outside of our scope of attention, even if it’s perfectly visible, you won’t see it.”[xiv] Just think about the last time you drove your car. Yes, as you drove you were aware of the street in front of you and to some extent what was on the sidewalks lining both sides of the street. But you couldn’t really fully describe something you saw (or were aware of) on the sidewalk, unless you turned and gave it your attention. There are some fun Youtube videos that demonstrate this type of change blindness. View these in order and try to follow the instructions exactly for the videos. Here’s a good one  And here’s another good one. Here’s a follow-on video.

The second conclusion is that perception is “gist-dependent.” Noe explains that gist-dependent means that if there are changes that alter the gist of the scene we are looking at, we’re more likely to notice them.

The third conclusion, and this is a big one to me, is that the brain does not appear to “…build up internal models of the scene.”[xv] Essentially, our brains don’t integrate the information perceived across successive periods of attention i.e., the brain does NOT put all the separate pieces, or pictures, together. This, as Noe tells us, is contrary to “traditional orthodoxy,” which is also known as the “snapshot” theory of vision. Noe says further that even if the brain did work this way, we obviously have little or no access to the information, because if we did have access to the information, “…then presumably we’d keep track of change better than we do.”[xvi]

Noe tells us that there are some who believe that the work being done on change blindness supports the Grand Illusion hypothesis. For example, philosopher Susan Blackmore and her colleagues say:

“we believe that we see a complete, dynamic picture of a stable, uniformly detailed, and colourful world, but [o]ur stable visual world may be constructed out of a brief retinal image and a very sketchy, higher-level representation along with a pop-out mechanism to redirect attention. The richness of our visual world is, to this extent, an illusion.”

Another says:

“despite the poor quality of the visual apparatus, we have the subjective impression of great richness and ‘presence’ of the visual world. But this richness and presence are actually an illusion. . .”

Of course, the reasoning displayed by the above remarks has the same problem as the blind spot discussion started by Dennett’sstatements. Do you see it? The underlying presupposition beneath Dennett’s statements and his peers above is that we all believe that when we look around we see a complete, stable, dynamic, uniformly detailed and colorful world. And Alva Noe says no, this is not a belief we all have, although he agrees wholeheartedly that we certainly do have “perceptual access” to a world that is richly detailed, complete and gap-free.”[xvii] He says further that, “We take ourselves to be confronted with and embedded in a high-resolution environment. We take ourselves to have access to that detail, not all at once, but thanks to movements of our eyes and head and shifts of attention.”

Noe then repeats a question posed by psychologist Ronald Rensick (perhaps Noe’s intent is to pound one of the final nails into the Grand Illusion coffin):  “Why do we feel that somewhere in our brain is a complete, coherent representation of the entire scene?” Again, Noe answers by telling us that this question rests on a false presupposition. “It does not seem to us as if somewhere in our brain there is a complete, coherent representation of the scene. Perceptual experience is directed to the world, not to the brain.”[xviii] (italics are mine).

Before I can put the topic of the Grand Illusion to bed (cursed with a restless sleep, no doubt), I want to share Alva Noe’s thoughts and comments to yet another potential objection someone who believes in the Grand Illusion might ask, because it raises a valid question: If people really don’t believe that they have detailed pictures in their head when we look at the world (i.e., the snapshot theory), how can we explain why people are so surprised when they are faced with the results of change blindness? Doesn’t the fact that we are surprised by  the results imply that we are fully committed to the “…problematic, snapshot conception of experience?” Noe tells us that this is a point raised by Dennett, as well.

Ever confident, Noe agrees that this is an important question, but in the same breath tells us that it is also an easy question to answer. That people are astonished when confronted by the facts of change blindness does indeed show that their beliefs have been upset by the demonstrations, but not because we are all committed to the snapshot theory of perception. Rather, our surprise is due to our tendency to think of ourselves as much more observant of changes than we really are, or that we are more immune to distractions than we really are. Think about it. This makes good sense to me.

Noe then takes this question and turns it back at the naysayers. He reminds us that while surprise requires an explanation, so does not being surprised. He asks us to notice something interesting – that “we are not the least bit surprised by our need to move eyes and head to get better glimpses of what is around us. We peer, squint, lean forward, adjust lighting, put on glasses, and we do so automatically. The fact that we are not surprised by our lack of immediate possession of detailed information about the environment shows that we don’t take ourselves to have all that information in consciousness all at once. If we were committed to the snapshot conception, wouldn’t we be surprised by the need continuously to redirect our attention to the environment to inform ourselves about what is there?”

There is one more significant issue that needs to be addressed before we can put the Grand Illusion in its proper resting place, but I will leave that for the next post. I probably have given you enough food for thought that you could make several meals.

[i] Noe, Alva: Is the Visual World a Grand Illusion? Journal of Consciousness Studies, 2002.

[ii] Ibid.

[iii] Daniel Dennett, Consciousness Explained, 1991, p. 356.

[iv] Noe, Alva: Is the Visual World a Grand Illusion? Journal of Consciousness Studies, 2002.

[v] Ibid.

[vi] Noe, Alva: Is the Visual World a Grand Illusion? Journal of Consciousness Studies, 2002.

[vii] Ibid.

[viii] Ibid.

[ix] Ibid.

[x] Ibid.

[xi] O’Regan et al. (1996; 1999); Rensink et al. (1997; 2000); Simons & Levin (1998).

[xii] Noe, Alva: Is the Visual World a Grand Illusion? Journal of Consciousness Studies, 2002.

[xiii] O’Regan et al., 2000.

[xiv] Noe, Alva: Is the Visual World a Grand Illusion? Journal of Consciousness Studies, 2002.

[xv] Ibid.

[xvi] Ibid.

[xvii] Ibid.

[xviii] Ibid.

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