Distortions

Distorted
Link to source

Today the sky is covered in an uneven grey padding, muffling the light. The tops of the trees are struggling in the wind. Yesterday when I woke late the blue was rich and clear, with the February sun strong enough to warm the floor. The blue is an illusion, isn't it, the effect of the white light from the sun bending through the prism of the atmosphere. Blue bends best and that's why it reaches our eyes. 

The earth's atomosphere is the lens between the sun and our eyes that register it as blue and our minds that add the harmonics and associations of summer, of beauty, of joy. Without the atmosphere the sky would be white. Without our eyes it wouldn't be any colour at all. Without our minds it would be meaningless.

Distorting lens

Yesterday I went to the opticians to have one of the lenses taken out of my spectacles. Since the cataract operation I have a new lens inside my eye, so I don't need a lens outside my eye any more. Well, at least not as strong. So until I can get a stable prescription I am advised to do without. The problem is that when the optician took the right lens out, the world looked so fractured I felt dizzy and had to sit down. 

You know that feeling you get when you try someone else's glasses that are far too strong for you? The disorientation is visceral. Like those episodes on television when the protagonist has been drugged and vaseline is smeared around the lens. And like the distorted photo at the top of this post, you can't help squint at it to make it make sense. 

On my walk home there were two of every person on the street, two of every dog and two lamp posts. Somehow I didn't bump into anything. Later in the day I could wear the glasses, but looking in some directions the world was fractured in several directions as if I were looking through a broken window. 

Distorting brain

Something like this has happened to me before. I remember sitting somewhere near the back of  the big lecture theatre at medical school, where a biochemistry lecturer was preparing his talk by writing a very long word in large letters over the four immense blackboards around the back of the stage. I can't remember what the word is, and I'm dredging through the murk that's been undisturbed since then. It's trying to tell me it was:

FLOCCINAUCINIHILIPIFICATION*

but I'm pretty sure it was actually:

DEOXYRIBONEUCLEIC ACID 

I am looking down on the word from above and can just about get the whole of it into my visual field at the same time without moving my head. The lecture theatre holds the whole of one year of medical students, over a hundred people, and is raked so that everyone has a good view. 

The lecturer has a big round head with the skin showing through the hair, the clothes of someone who doesn't think about clothes, and the big precise fingers of a man who's accurate with a pipette. As he talks he paces from one side of the stage to the other, looks up at us as he turns, and then paces back again. I start to feel sick. Which is a pity because it's lunch time and I like the cheap chicken pies they sell in the student's union bar. The inside of my head feels like cotton wool and I'm not taking in the lecture any more. Which is a pity because I don't like revising.

A few minutes later, in some perplexity, I realise that what I'm seeing down there on the blackboards is not DEOXYRIBONEUCLEIC ACID any more. It's changed to something oddly different that I can't quite put my finger on. And the effect of the difference, like something out of a 1950s alien invasion film, is to make experience of being me, here sitting on the high bench with my arms on the hard desk, eerily unfamiliar. As if I'm perhaps not one lump of body but several, in different orientations to each other than usual. And as if the illusion of the world around me is developing air bubbles under the surface. 

And then I notice that the word that I am seeing there in front of me is actually 

DEOXYREUCLEIC ACID 

The middle is missing but without any gap to show where it should have been. 

And it turns out that this is also true of the whole lecture theatre - it is narrower than it used to be and the lecturer is moving from the left hand side of the stage a few paces, vanishing in the middle (but still making pacing sounds and speaking), and then appearing again to continue walking across to the right side. I turn my head and check for myself that the rest of the world is still actually there and it's my eyes that are mistaken. It is. By the time I get to the ladies I'm throwing up. 

You've probably guessed by now that I was experiencing the neurological aura of a migraine headache. So I know from personal experience that what the world looks like is not directly translated into what we are seeing. And yesterday when I was sitting in the opticians and looking at a fractured world I knew that my brain was interpreting what it received wrongly.

Turning the world upside down

In 1896 George Stratton published a paper** about an experiment he did. The part of the eye that has the nerve cells which bring the image to the brain is called the retina, which is like wallpaper laid inside the back of the eyeball. Biologists had noticed that the image that appears on the retina at the back of our eyes is upside down and back to front, with the sky at the bottom and the ground at the top, the left on the right and the right on the left. So the image of the world that reaches the brain is upside down and back to front. This is obviously weird and interesting, as we don't experience the world that way. Stratton wanted to know if this inversion was necessary for us to see the world as the right side up. So like all good Victorian scientists he experimented on himself. 

He made a contraption that he wore in front of his eyes that flipped the image, so that what appeared on his retinas was actually an upright image, with the sky at the top and the ground at the bottom. The left on the left and the right on the right. He wore it continuously for three days except when he slept, when he was carefully blindfolded to ensure he had no experience whatever of normal vision during that time. 

He took a while to learn how to move towards things he could see. If you have ever tried playing a computer game with the console upside down, or reverse parking in London, you have a tiny inkling of how difficult it would be to negotiate a world where left was right and right was left, with the ceiling beneath you and the floor above. 

The result of Stratton's experiment was that even in as short a time as three days he became able to integrate his visual experiences to the degree that he could move towards objects he could see, and predict where the sensations would be when he reached them. So the straightforward conclusion to his experimental question was that there is no necessity for the retinal image to be inverted. The brain adapts to the way it is presented. 

Other experiments with distorting goggles demonstrate not only that the brain can adjust, but that when the googles are removed the world seems distorted without them for a short while. Which reinforces his conclusion, and is of course reassuring to me in my current situation.

Keeping your head 

However, Stratton was struck by how different his experience was of the parts of him he couldn't see. His head and shoulders, were stuck in the old paradigm in the old position in relation to the ceiling, and he experienced them as if he were somehow looking from between his legs at the world. I imagine he must have had something like the feeling of eeriness and dislocation that I experienced with my migraine aura. Even though that strange arrangement of his body parts was obviously an illusion, it was one which didn't change during this experiment. 

When he extended his experiment to eight days, he found that his interpretation of what he saw was still sometimes interfered with by recurrences of his inverted world expectations. But that his head remained stubbornly between his legs.

The experiment has been repeated over the years with volunteers who found similar results - after a while their world did not appear inverted, they did.*** 

Experimental results

To me there are some interesting things about this experiment. 

1. The adaptability of the brain to changes in the appearance of the world outside it. 

Today most of my world is no longer distorted and I no longer feel dizzy. It's only when I look to the right, with most of my perception coming through the new lens, that I see double or compressed images. 

To me there's something humbling about this. Not because the brain is amazing (I'm a psychiatrist, I knew that already!) but because it's yet another indication that we can't know everything. 

I think of myself as a scientist and I know how much knowledge about the world has been revealed by constructing experiments to minimize the subjectivity of the results. I'm not saying it isn't worth trying. Just that there is so much more subjectivity in our experience than we can ever completely compensate for. That there is so much more about reality than the little we can know and that's not because we haven't done enough experiments yet. It's just how it is. 

2. The persistence of the self-image of the head. 

The parts of Stratton's body that he couldn't see were preserved in their original position, even when the apparent positions of the other parts made that absurd. The same effect happened with the volunteer subjects in the 1990s.*** The world didn't appear inverted, they did. Even though we have never been able to see those parts of ourselves directly (only in the mirror), we persist in believing we know where they are even when it makes the world absurd. Hm, interesting. I'm going to let that one percolate for a while.

3. The resistance due to expectation. 

And the experiment brings up another idea redolent with significance, to me anyway. As Stratton put it, 'the difficulty of seeing things upright by means of upright retinal images seems to consist solely in the resistance offered by the long-established previous experience.'

While our long-established experience of what the world looks and feels like and how people think and behave is useful as a shortcut to understanding our circumstances, and sometimes necessary to keep us safe, this reliance on experience comes with the cost. The cost being not just reluctance to see what's actually staring us in the face, but an inability to accept that it is happening at all. That what helps us adapt to reality in most circumstances is not our thinking it through and understanding it, but the marvellous adaptiveness of our brains over time.

Conclusions

To put it in a more pragmatic frame, perhaps the car keys were in the first place I looked but my mind, assuming that they wouldn't be, couldn't accept what it was seeing. Perhaps, unlike my busy mother, professional nurses don't resent the time they spend caring for me after an operation (see Feb 1 post for context). In my head I know it, but I experience it as otherwise. Perhaps because, like Stratton, the 'resistance of my expectations' stops me from seeing that now is a different reality at all. 

What would it be like if we could learn to trust the marvellous adaptiveness of our brains over time and approach our experience as if we had no expectations? 

It turns out that sitting there in the optician's, as soon as I remembered Stratton's experiments I accepted that distorted was how my visual experience was going to be for now. I accepted that I had no option but to sit with the world fracturing around me. When I let go into this, I found to my surprise that I knew that everything was all right. When the clouds are gone, the meaning is contentment. That's the way minds work. 

*a silly word meaning 'the act of deciding something is worthless', a word you only need for spelling bees and when what you need is an unfeasibly long and worthless word.

**Link to pdf of Stratton's paper

***Link to a 1999 paper exploring the effect of non-inversion in a much more sophisticated way. The introduction bills it as a debunking of a myth of a return to upright vision. But from the discusion it is obvious that this refers to the idea that the image is somehow turned upright. It  concludes that the adjustment to a new apparent orientation of the world is not in the image arriving at the brain, but in part of the brain itself, at least partly in the parietal cortex.