LM: Hey Kiv – we better check thus out – your warning light is on
Crazy Kevin: Yeah I know hey bro’. It comes on a but – bin on sunce before Gundagai. Doesn’t seem to be a problem though ey?
LM: It might be Kiv. Why don’t you take a look in the manual, see what utt says?
CK: Naah. It’ll be alright bro
He seemed to not worry at all about it, but it did concern me. I had driven my girlfriend’s dad’s car for a few minutes after the exclamation mark light came on and ended up with a cracked head gasket (on the car, not on me). So, I was pretty insistent with Kiv. He cracked.
CK: Alright yer bug worry wart. You keep drivung and I wull fux utt up.
With that, Crazy got something from under his seat and then leaned over towards me. He stuck his head up under the dash. He was fiddling around there for a while (this made me a little Uncomfortable), and then with a final click, something happened and the light went off. He came out with a little globe in his hand.
CK: There utt is. No worries now. Won’t bother you a but.
This was indeed a novel strategy and one that didn’t sit too comfortably with me. I drove on and, funnily enough, forgot about it. That is until we passed the turn off into Narrandera, at which point we headed south toward Deniliquin and the Mallee country. This time a big P illuminated on the left of the dash, just above where the exclamation mark had been.
LM: Hey Kiv, what does P mean, on the dash?
CK: Stuffed uf I know bro’. Panic? Ho ho fruggin ho?
LM: Thunk we should stop Kiv? Take a look under the bonnet perhaps?
CK: Naah – I’ll fux utt up – I know cars
Again he leaned over and fiddled behind the dash, emerging with another little globe and a look of satisfaction. The most amazing thing was how easily I tended to forget about the two little lights. We went another hundred miles or so when a third light came on. This one looked like a water jug.
Again, Crazy just leaned over and emerged a few minutes later with the globe. He was positively chuffed with his little haul of globes and began tossing them back and forth in his hands. The thing was, I began to think that this was truly avoiding the problem – the ute was running well, it didn’t seem sick in any way, and Kiv seemed to know exactly what he was doing. The last light to come on had a picture of what looked vaguely like a foot on a brake pedal. I told Kiv and this time he lent right across me and pulled a fuse out of the little black box near my knee. All the dash lights went out.
CK: “Sorted hey Bro’. Now you won’t get any lights tellung you anything now.”
Sure enough, we rolled into the Commercial Hotel in Kaniva at 11.46. We were just in time for last drinks and the barman signed my card: “23:52 Friday.” It had taken me 12 hours and 52 minutes to travel 1165 kilometres. That is unbelievable hitchhiking time.
After closing, Crazy set up the swag8 on the back of the ute and I slept under the tray. The sun came up about a millisecond before the council street cleaner sprayed me with water. We were both up and Crazy got in the ute so he could see this Bull Mastiff first thing – his theory was that dogs are always grumpy before breakfast, so before breakfast was the only time to tell for sure if it was a “Heckyl or a Jive9 – makes all the difference”. I bid him farewell and he took off up the main street.
I have this thing about watching people as they drive off. I have to watch them until they are out of sight. I think it is a legacy of standing on the street as a kid waving my grandparents off as they headed back home after a couple of weeks with our family. Nanna would have her arm out waving the whole time and we would all wave as long as we could see them and then turn around and notice Mum’s tears, not really knowing what to do about them. Crazy was no more than a couple of hundred yards away when his left indicator came on but I could hear the ute accelerating into the corner. In fact, it didn’t turn the corner at all. Instead it just accelerated straight across the road, jumped the kerb and blew up. It turned into a speeding fire ball, still accelerating, careering across a big carpark until it met with a brick fence at which time it stopped dead still, on fire, back wheels spinning madly in thin air.
Crazy Kivin dropped out onto the ground and crawled away. By the time I got to him he looked bad. There was a whole lot of blood. He already had a lump the size of a golf ball on the left side of his forehead and a gash across his cheek. He explained that the steering and brakes went and the car just started accelerating. Nothing he could do.
CK: I hope that guy from the Kaniva Times got a shot of the old girl blowing up. That’d be my 12 minutes. But you know the worst thing?
LM: What Kiv? What’s the worst thing?
CK: I’ll not know if that Bull Mastif is a Heckyl or a bloody Jive.
so, what does Crazy Kivin’s brush with death have to do with pain?
The one sentence take home message: Pain is a critical protective device – ignore it at your own peril.
If Nigel attempted to ‘anaesthetise’ the problem with his SuperSkoda, then Crazy Kivin might have been taking some more drastic measures. The whole point of warning lights on the dash of a car is to tell you, the driver, that something requires action. Sure, you can do things to turn the light off – to anaesthetise the dash perhaps. To surgically remove the apparent culprit, or end up doing neurolysis10 on the whole electric supply, but if your clinical reasoning is not sound, then there might be a major cost. The cost for Kevin was not simply that part of his ute that was in danger. Rather, the cost for Kevin was (almost) everything. Death. Kaput. All over. Both Crazy Kivin and Nigel were attempting to remove pain, rather than remove the cause(s) of pain. In Nigel’s case, it was a specific pathology (problem) with the engine’s attachment to the car. In Kivin’s case, there were many contributing factors and he just kept removing his ute’s ability to tell the driver about it.
It is clear that both Nigel and Kivin were spectacularly stupid people. If they ever read this I imagine they will think the whole thing is a tribute to their cleverness. That is another amazing thing - Kivin convinced me that what he was doing was not stupid. Simply by knowing a whole lot about cars, or at least seeming to, I figured there was no reason to doubt him.
I think there are plenty of things about these stories that make them useful metaphors for patients in pain. They remind us that pain is a warning system, which usually gives us early warning of something in the body going, or about to go, awry. To devise strategies that effectively remove that system is, ultimately, going to be problematic. In this sense, I have told this story to patients with the following types of issues:
Athletes who push their bodies so hard that the normal pain protective system doesn’t work very well. If patients don’t change their behaviour in response to pain, then pain hasn’t achieved its goal.
Patients who don’t care what is wrong with them as long as they can find someone to ‘block it again’, or a drug that will turn it off, so that they can go back to their full lifestyle straight away without having to actively do anything to help themselves (in a rehabilitation sense).
Patients who are keen to use TENS or drugs as their main pain management strategy. This scenario is similar to (2) but also slightly different. For the TENS thing, I find patients are really receptive to Nigel’s SuperSport 110 story because of the whole turn the radio up so that the fuzzy noise is louder than the noise coming from the problem – it is an obvious link to the proposed mechanisms of TENS – to use non- noxious11 input to inhibit the noxious input.
Those patients who tend to avoid things because they know that they will hurt. I use Crazy Kivin’s strategy of simply removing the light globes that lit up the various lights as a metaphor of the way some patients tend to avoid the pain, but don’t address the underlying problem.
seeing is believing
Or: pain doesn’t provide a measure of the state of the tissues.
I remember quite clearly being told about how visual perception works. I was sitting up the back of Mrs Smart’s
Social Psychology class at Hawker College. I chose social psychology as an elective because my brother did. For some reason I had come to expect that doing psychology would make me a better person, or it would at least increase my chances of developing deeply rewarding relationships in the future. There was, after-all, no higher calling than ‘to relate’ (jeepers I took some things too seriously – while I was learning social psychology my mates were doing experiments with grasshoppers and planning how to pash Suzanne Jackson behind the tennis wall). I think my mum had been able to convince me that I was naturally good at psych-type things so I figured that doing it at school would get me a few easy marks. The first unit, Visual Perception 101, was pretty easy. According to Mrs Smart, visual perception works like this:
If you point your eye in the direction of something, the light that is reflected from that thing enters your eye, goes through your lens and then hits your retina. Upside-down. Everyone always remembers that – as though it is one of the most remarkable things in the entire animal kingdom. I reckon it shows how boring the rest of it must have been. Your retina consists of millions of cells that are super-duper light receptors. Different types of light receptors are activated by light of different wavelengths (it is the different frequencies that we end up seeing as different colours – actually I think colour depends on the relationship between the light energy and its wavelength – but all that is a bit beside the point here). Activation of these receptors causes action potentials in the neurons of your optic nerve12. The optic nerve runs to the primary visual cortex, which is in your occipital lobe. The primary visual cortex consists of 20 million neurons, which flip the image back the right way so that you get a conscious experience of the light that is entering your eye.
This, apparently, was vision. I learnt later, in physiotherapy school, that there are cones and rods and a fovum and the yadda yadda yadda layer13. Despite this substantial leap in knowledge of the visual system, the principle seemed the same and that is: the visual system is a very specific and reliable system so that what you see is what you get – you see a direct representation of what is entering your eye.
I am not sure that Mrs Smart’s Social Psychology class lived up to my expectations. Not all was lost though - my mates didn’t gain too much from their grasshopper experiments, nor from Suzanne Jackson I imagine. One thing that Mrs Smart did leave with me however, was a restless whispering in the back of my mind, that surely it can’t be that simple. Here are three questions I asked Mrs Smart:
Do we really need 20 million neurones in the visual cortex just to flip an image?
How do I see things in my sleep if my eyes are closed?
How do visual illusions work?
This is how the conversation went:
LM: That seems a rather large number of neurons and a large amount of space, just to flip the image back the other way. Why don’t we just have another retina there and use the spare neurones and brain space to think with?
Mrs Smart: Lorimer my boy, we are indeed fearfully and wonderfully made.
LM: What sort of a ridiculous answer is that!
I didn’t actually say the last bit because Social Psychology had taught me that to do so would not be conducive to mutually respectful interaction. However, I did think it and I reckon I may have even mouthed the “Wha-“ before regaining an attitude of mutual respect over my motor output.
This interaction dealt my naturally inquisitive nature a steady blow. Up until then Mrs Smart had been right up there with Mary Poppins and Carla (Captain Kremmen’s wonderful assistant on the ‘Kenny Everett Video Show’) as truly unfaultable women. But “we are indeed fearfully and wonderfully made” really got me. I had all these insulting lines running through my head: “Smart is obviously not your maiden name” etc etc. Even though I was not the sort of fellow who would normally express myself in that way, it was probably only my substantial crush on Mrs Smart’s daughter Naomi, that stopped me.
So, the whisperings in my mind stayed with me, right up to physiotherapy school. I was so excited about Perception with Professor Ron Balnar, that I arrived for the first lesson pretty much on time. It is the only time I can remember that I was first to class. I liked Prof Balnar – he had this peculiar habit of taking a very large stick with him wherever he went. He would start each lecture with something like:
“Mmm, my stick, large isn’t it? Anyway, it won’t be going anywhere. Was tree just weeks ago I’m dashed – such is the way though. Such is the way. Tree to stick. Matter of connection. And context I guess. Now there’s a thought…”
Like most nutty professors, he seemed to be terrifically clever and terrifically stupid at the same time. I was sure that his knowledge of vision would calm my disquiet. I waited with bated breath for him to answer my three questions as he took us on a tour of the human nervous system. He doddered on until I lost patience and asked him directly:
LM: That seems a rather large number of neurons and a large amount of space, just to flip the image back the other way. Why don’t we just have another retina there?
Prof Balnar: Yes, yes it does doesn’t it. Yes. Good point. Quite so. Would a retina work there? Mmm. Would it. Not sure. Good point. Good question. Might evolution have missed that? Not all luck of course. Where is my stick?
So. Prof Balnar was about as helpful as Mrs Smart. As it turns out, Mrs Smart’s position on it has proved more useful for me than Prof Balnar’s – every time my neuroscience journal contents email alert pops into my inbox, I become more convinced that we are indeed fearfully and wonderfully constructed. Mrs Smart has become the new whispering in my head.
I headed into the textbooks. It seems that there is a great deal more going on when we see. This is some of what I learnt:
Light does in fact reflect off your environment and land on your retina and it does in fact invert on its way through your eyeball, which means it does land on your retina upside down (thank God for that – what would we have done if we leant that that was a bumsteer?!). Light does in fact stimulate cones and rods on your retina and it does in fact send that information through your optic nerves to the back of your brain – your occipital cortex. That is where the story becomes fundamentally different. A most magnificent thing happens: instantaneously and without you knowing, your brain calls on all sorts of previous experiences: the things you have learnt - things that you know that you know and things that you don’t know that you know, your expectations, other sensory inputs, explicit memories and implicit memories.
All of those things can activate neurones in the brain, which in turn can mould and massage, modify and modulate the information that has been sent from the retina. The conscious experience of vision emerges after this highly sophisticated modulation process. There is no doubt that light hitting your retina is very very important, but light is neither sufficient nor necessary for you to have a visual experience. Proof of the former is found in visual illusions, when you see things that are not there. Proof of the latter is found when you dream and your eyes are closed. That points to what I reckon is a really important thing - your brain creates your visual experience. That visual experience is not simply a picture of what is entering your eye, it is an interpretation of that information.
What we see, then is not ‘the facts’, but a sensible image, based on the original light information, but modulated, perhaps tailor-made, for you14.
Take for example, figure 1. Do the lines look the same length? Even if you have seen this before and you know that they are the same length, they probably look different.
Figure 1 Lines of the same length look different
Try looking at this picture for just a split second – a backwards blink if you like. Notice that they still look different! Try looking at it for a while and try to make the lines look the same length – you can probably feel that you are trying to block out certain bits of information in the picture. You might have some luck by making your eyes go sufficiently blurry so as to make the lines almost impossible to detect.
But then the picture is completely meaningless.
Taking into consideration things that you know (but you don’t know that you know) is not just about geometry. Have a look at the image in figure 2. In this figure, square A is definitely darker than square B right? Wrong.
If you don’t believe this, grab a piece of paper and cut out holes for the panels. So, what is going on there? Lots, apparently. The caption quotes the inventor of this illusion in his explanation. If you are interested, take a look at his chapter on this type of thing in the reference list Ref List No. 2.
If you are like me, you might be satisfied with a fairly broad explanation like this: in a split second, and outside of your consciousness, your brain processes a great deal of information and calls on a great deal of previous knowledge. You don’t know that this is happening. The first thing you are aware of is that you see a sensible and meaningful 3-dimensional picture. This is a conscious representation of what is really there. It is not accurate, but it is meaningful and sensible.
Figure 2. The same colour illusion
This illusion, and the one at the front of this chapter, in which the two diamonds are really the same shade of grey, shows the way the brain can modulate light information so that it makes sense, rather than give you a truly accurate conscious experience of what is hitting your retina. This one is called the same colour illusion, published by Ted Adelson in 1995 (it is sometimes called Adelson’s checker shadow illusion).
Painful Yarns Page 2