Chloe Banks

And so we conclude our look at the the more interesting aspects of brain disorder with an unashamed study of some fascinating, but more or less random disorders: Alien hand syndrome, Phantom limbs, neglect of a hemisome, synaesthesia and blind sight.

To understand some of these it is first important to understand something fundamental about the brain: you not only need to be able to do things, you need to know that you can do them. So, you not only need to be able move your legs when you want to walk, you need to know that you are moving your legs, or you'd get very confused indeed! Therefore the parts of our brain that tell us to do things, such as hear and taste and move, have "association cortices" (sing. cortex) that let us know we're doing it.

Alien hand syndrome, while mocked in the modern media on programs like the League of Gentleman, is a distressing syndrome that leaves the sufferer feeling like they can't control a part of their body. It is as if they have been possessed. This is often a hand but can be any part. The affected part will perform tasks seemingly without being "told" to by it's owner and often appears malignant in intent - such as undoing buttons that the sufferer is desperately trying to do up with the unaffected hand. It is possible that this is caused by a breakdown in communication between parts of the brain that control movement and consciousness of movement, as it is often seen in people who have a brain that has a severed connection between the two halves.

Phantom limb is a better-known condition, affecting amputees. A part of the body that has been severed can still be felt as if it were still attached. This is often felt as pain or unbearable itching in the "phantom" part of the body. The most likely cause is the continued stimulation of the severed nerve - after all we do not feel pain in any part of the body except the brain, our brains just work out where the pain signals are coming from and tell us that it is our leg or arm or head that is hurting.

Neglect of a hemisome (one half of the body) is very rare, but oddly fascinating. It is exactly what it says on the tin: a person does not acknowledge that one half of themselves, or even the world around exists. So, give them a blank clock and ask them to fill in the numbers and they will put them all on, but crowd them into one half of the outline. They will only eat food on one half of their plate - absolutely convinced that they have eaten it all - and have to learn to turn their plates round once they're "finished" so they realise there's still more to eat. It isn't a conscious choice, those afflicted genuinely don't realise the other half of the world exists. As far as I know it is still a very little-understood condition.

Synaesthesia, on the other hand, may be a lot more common than we think. It occurs when the wiring that connects our senses to our consciousness get a bit entangled and we are then able to mix up our sense. Some people can taste words for instance, so every word has a distinct flavour (as was so beautifully illustrated in the documentary "Derek Tastes of Earwax"). More commonly people can see sounds as bright colours or shapes, or can hear colours,or associate numbers, months or days etc. with distinct personalities. It is thought that many of our greatest artists and musicians may have been aided in their work by a greater or lesser manifestation of this condition. It has been reported in David Hockney, Wassily Kandinsky, Franz Liszt and even the physicist Richard Feynman (who sees equations in colour).

Finally, perhaps most fascinatingly, blind sight: people who can see but don't know it. These people have perfectly functional eyesight but the connection between the bit of their brain that sees and the bit that tells them they can see doesn't work and so, as far as they are concerned they are blind. If you asked them what they can see they would say that they can't see anything, yet if you asked them to walk down a corridor littered with obstacles they would probably be able do it without bumping into anything at all.

With millions upon millions of wires tucked away in our heads, each connecting with many others, and with everything we do depending on several accurate signals passing along the right pathway, perhaps it is less amazing that these conditions exist and more amazing that, most of the time, our brains work just perfectly.

So, if our brains are so complicated (see previous post) what are the consequences if something does go wrong? With no immune system of its own, our bodies do absolutely everything they can to stop viruses and bacteria entering the brain in the first place, but no defence system is completely infallible and, in reality, most brain trauma is caused by a faulty bit of wiring or some physical trauma such as a blow to the head or a blood clot.

We have some mechanisms for dealing with this trauma. Unconsciousness is the first. Blacking out is caused by insufficient blood to the outer part (cortex) of your brain. This can be caused by a variety of things, from standing up too fast to brain swelling or even emotional trauma. In reducing the blood supply to the cortex, more can go to the brain stem which keeps you alive. The brain stem has a much higher tolerance of low oxygen - i.e. oxygen levels dropping slightly might incapacitate your cortex but they have to get quite considerably lower before the brain stem gives up. Which, all things considered is a good thing, as once your brain stem has given up you are officially dead, with no hope of revival.

In case you are one of those people, like me, that has an irrational fear of being buried alive do not worry. Brain stem death has to be proven by a couple of doctors independently before you are declared dead and you will be put through a battery of tests to make sure you really are making your exit. The brain stem is the primitive part of the brain which controls reflexes so if you have any reflexes left at all you cannot be declared dead. These innate reactions include breathing, swallowing, flinching from pain, pupil dilation and gagging (all of which can be tested, so if you wake up with someone sticking something down your throat trying to make you gag, count yourself lucky). But there are also charmingly quirky reactions such as the flicker of the eyes when water is poured into one ear (I'm not joking, it's a recognised test for brain stem death).

In short then, unconsciousness may have once been seen as a sign of death, but no longer. In this country certainly you are not going to awake to find yourself laid out on a slab in the morgue after hitting your head during a game of ultimate frisbee, as before the bag is zipped over your head someone - probably two people in fact - will have stuck things down your throat, pricked your face with needles, shone lights at you, touched your eyeballs and poured water in your ear. And after all that, you'll probably be glad of the peace and quiet.

The human brain is a funny thing. All around the world scientists have spent and are spending their entire lives studying one tiny cluster of neurons in one tiny area of the brain and yet, despite this massive joint effort, so much remains a mystery. Perhaps we will never be fully able to understand something that we need to use in order to understand it?

It really is something quite remarkable; millions and millions of nerve cells (neurons) connected to each other via chemicals, released through bursts of electricity. It is so vastly complex that, are we to damage it, it doesn't even try to mend the broken connection - the consequences of getting the repair wrong may well be far graver than not attempting the repair at all. Perhaps because of this very fact, we will do almost anything to protect our brain: We will sacrifice any other part of the body to save our brain. It is wrapped in three membranes (meninges), cushioned by copious amounts of fluid and shielded by an armour of bone, yet it contains no immune system itself and, despite the mind-boggling number of neurons it contains, is unable to feel anything at all (which is why it is perfectly possible - indeed, even desirable - to carry out brain surgery with the patient fully conscious).

Over the centuries as people have strived to understand the brain there have been two dominant methods of research. The first is the, frankly disgusting, practice of experimenting on prisoners of war. It would be a little comfort to say that these crimes were confined to the ancients where prisoners taken in battle were counted as sub-human and that, in our more enlightened times, it was not possible to get away with such things. It is not a comfort we can take though as at least one prominent Nazi spent much of the war years carrying our experiments in his concentration camp (a Nazi who, by the way, was never brought to justice after the war and may indeed still be alive today).

The other, more reputable, source or information is by studying, with consent, people who already suffer from some form of disorder of the brain. The most famous case of all is probably that of Phineas Gage who highlighted the importance of the frontal cortex of the brain in the making of personality, by accidentally blowing his out with a tamping rod while building a railroad. His change from mild-mannered family-man to violent, unpredictable thug was a personal tragedy in the greatest terms but has made him textbook fodder for years. Similarly the sensations experienced by epileptics before they have a fit have helped identify the areas of the brain associated with the various senses and one mild-mannered man unable to make any new memories at all has done wonders for the study of learning.

There are some wonderfully engaging facts and fascinating disorders (fascinating that is, if you are fortunate enough not to suffer from them) that I could spend hours writing about. The fact that's men's brains are no bigger than women's but DO contain more neurones in one area (and yes, that area IS the bit you use for map-reading)is just one such titbit to tantalise you with. But I fear you stopped reading a long time ago and a discussion of Alien Hands, people who can taste words, blind-sight and Phantom Limbs will have to wait for another day.

We walk on two legs. You may have noticed that yourself. You may also have noticed how we're the only ape to do so. Sure some of our closer relatives can support themselves on two legs for short periods of time, but none actually wander round that way by choice. So why do we? If four legs is good enough for other primates, why did we evolve differently? Are we just the crazy mixed-up kids of the primata order?

Well firstly, why shouldn't we? Everyone needs to find their niche somewhere, ours was in the sphere of bipedalism. But you are of course quite right in thinking that there must be something more to it than that. We're just not quite sure what. After all, to make the change from swinging through trees like spider monkeys, using lower branches to support our locomotion like orangutans, or even from knuckle-walking like gorillas, we needed to make some fairly massive changes. Our pelvis had to flatten and flare out at the top, the angle at which our limb bones joined to each other had to shift, we had to develop huge gluteal muscles (the ones in your backside) to pull our legs backwards properly (apes mainly just use their hamstrings) and we then had to alter the point at which our spines entered our skulls in order to still be able to look forward. That's a lot of effort just to stand out from the crowd.

Luckily several clever types have come up with a range of theories as to why we took that rather slow but dramatic leap over some millions of years. Perhaps it was for better temperature control as we emerged from the forests on to the baking hot plains; standing upright greatly reduces the surface area of your body directly struck by the sun's rays. Or maybe in our new environment we needed to be able to spot both prey and predators over long grass and from a greater distance. But on the flip side, the evidence would suggest we started our transition to two legs some time before we left the forests. Perhaps we were "aquatic apes" who learned to stand upright after spending so much time foraging in rivers with our weight supported by the water, or perhaps we became skilled hunters who benefitted from being able to cover ground quicker and more efficiently. Many people back the theory that it simply left our hands free to collect fruit, make tools and carry weapons. But then of course you get into a "chicken or egg" situation: did we make tools because our hands were free, or did we evolve to have free hands in order to make tools?

And what do I think? Well I think it was probably a bit of many things. Those apes that could support themselves upright for longest were able to reach fruit that others couldn't, spot potential food and potential danger first and travel to it or run from it with less effort. They were the ones likely to survive longest and be healthiest and therefore the most desirable to potential mates. This mean that they would be the ones to pass their genes on to the next generation. As always, our most striking and fascinating characteristics as humans - whether that's opposable thumbs, specialist sweat glands or our quirky way of walking - comes down to two things: food and sex. Typical huh?

As a Christian and a scientist I am probably one of the least cool people around by today's standards. In a culture where we are invited to take extreme opinions in every situation, it is very unfahsionable not to fall on either the creation or the blind evolution side of the fence. I fell in love with the wonder of evolution first and then Jesus second. Although their order of importance in life is very much reversed now, I never saw the need to exclude one for the sake of the other. To me, a God that can create a world, indeed universe, that has the beautiful, scientific, simple complexity that we see around us, is worthy to be praised. I believe in a God of free will, I don't understand why that can't be applied to His creation as well as to the narrow limits of human thought. But I digress. This is not the subject of this post.

As I often think about the evidence that I found most compelling when coming to believe the gospel, I also think about the evidence I find most compelling when it comes to believing in the evolution of animals from our ancestors millions of years ago. That's really what I want to talk about.

I think from a strict 'creation vs. evolution' perspective, I can't help but feel that if we had been created exactly as we are now then an omnipotent God would have done a better job of it! Our bodies are amazing and wonderful things but we have some oddities that don't really make sense: our eyes are wired backwards for one. You would think that we would supply our retinas with blood from behind the eye in order not to get in the way of vision but we don't, our vision has had to adapt for their being blood vessels in the way. Similarly, the optic nerve has to snake its way all the way to the back of the brain to find the optical cortex, whereas a designer I'm sure would have thought to put the relevant part of the brain directly behind the eyes for efficiency.

We also have these cute little things called vestigial organs; parts of us that are completely useless. Or uselss that is in the modern human body. They would not of course be useless to our evolutionary ancestors. We have a tail bone but no tail. We have muscles to waggle our ears that are completely redundant. Then we have that little trouble-maker, the appendix. In herbivores the appendix is involved in breaking down the cellulose found in leaves and grasses. In humans it is, as far as we know, useless and can be removed entirely with no consequence.

My absolute favourtie hint at our genetic past though is our limb structure. Our legs and our arms contain one long bone (humerus or femur), connected to two smaller long bones (radius and ulna or fibula and tibia), followed by a lot of little bones (carpals and tarsals) then some small long bones (fingers and toes). And you know what? Every other mammal is exactly the same. This may not be shocking in the case of monkeys or even dogs and cats, but how about whales? Yup, still there. Inside those giant flippers of theirs you can find all those bones too. Or how about non-mammals? Snakes for example. Pretty cool huh? We have more in common than we think. But then that would make sense if we all evolved from the same starting place...

There is not enough time or space here to explore the subject even on a fairly shallow level however, we know evolution happens. We can see it almost in real time when we study bacteria, most notably when we come across "superbugs". Of that there can be no doubt. Humans may not be bacteria but I don't see how it is possible to deny evolution in humans either. If we didn't evolve at all then how come we all have different skin colours, for example? As to whether we really developed from the 'goo to the zoo to you'? My suspicion is that we did, but I also think that to the average man on the street, it probably doesn't matter that much. As it happens, I believe that we are fearfully and wonderfully made through a beautifully elegant, stunningly clever process of evolution. And praise God for that!

I have always been fascinated by the human body. I'm a little geeky I know, but there it is. It is just the most wonderful thing. Did you ever stop to think about it? Did you ever look at your hands when tying your shoelaces and come to wonder how you were able to perform such a precise and skilled action with no thought at all? Did you ever wonder how your body could have all these ways of keeping you at the right temperature (sweating and shivering for instance) and yet when you get ill it's able to override all of that so your temperature can rise? You probably didn't.

Humans have become the master specie over the whole planet. It is us and not ants, snails, elephants or squid that have the upper hand. So what is it that makes us so special?

The most obvious advantages we humans have are our big brains and upright posture. But I think it all started long before that. If you ask me, there are two reasons why an ape evolved to rule them all: we sweat like no other animal on earth and we can touch our thumb and little finger together. That's all folks. I can (and probably will at some point) rave for hours about how great our big toes are, how sneaky our reproductive systems can be and about all manner of other interesting quirks of these bodies we like to call home. But for now, contemplate for a moment your sweat.

The human sweat gland is brilliant. The structure and number of them we have gives us possibly the best cooling system in the world. Compared to most animals we can control our body temperature in a huge range of conditions. This is especially important when it comes to hunting. We humans have evolved very cleverly to be not the best at something - we're not the best runners or swimmers or climbers - but to be the most adaptable. This is great, right up to the point when you need to run down a gazelle in time for tea. A gazelle can run a very great deal faster than a man. Game Over you might think. Not so. A gazelle can only run for a short time before it overheats and must stop. A man in his natural state (i.e. reasonably fit and active, not a 21st century office worker) could run all day if need be, thanks to his sophisticated cooling system. And that's exactly what he does.

Off goes Gazelle at a sprint, off goes Man at a jog. Gazelle stops to cool down, Man continues jogging. Gazelle spots Man is close again and goes off at a sprint, Man continues jogging. Repeat for six or seven hours and eventually Gazelle is so hot it collapses, up comes Man and finishes Gazelle off in time for Woman to make a stew. And there's the protein you need to build yourself a nice big human brain.

And what of the opposable thumb? Well, I'm sure that doesn't need explanation. Without our wonderful fifth digit, humans would never have built houses, made fire and tools, been able to handle animals, tie our shoelaces or send text messages. What a different world it would be.

Sweat and thumbs: that's what being human is all about.

There will always be varying opinions on how much exercise we need to get to maintain good health or build fitness. One school of thought will say that “little and often” is the best way to approach exercise, whereas another will tell you that anything less than an intense thirty minute workout is a waste of time. In the end, it all comes down to who you are and what you are trying to achieve.

Different people will see different effects when they begin to exercise. Two people put on exactly the same schedule will not experience exactly the same rate of progress. Some people are naturally disposed to putting on muscle and will therefore respond quicker to weight training, another person will be able to lose weight quicker or will be more or less prone to injury. However, one thing that can be said is that exercise, tailored to suit an individual and their goals can have huge effects on fitness and physical and emotional health.

Most fitness professionals will use some basic guidelines, set by the American College of Sports Medicine (ACSM), to help a client work out what's suitable for them. The guidelines differ according to the goal of the exercise program. For good health, specifically the health of our heart and lungs and everything associated with their function, we need to be doing thirty minutes of exercise at least five days a week, but preferably every day. This alone can seem quite daunting but it is not a requirement to do all thirty minutes at once. So a ten minute walk to the bus stop on your way to work, a ten minute stroll to buy a sandwich at lunch and the ten minute walk back from the bus in the evening meets the criteria without any need for Lycra and heart-rate monitors. The only instructions are to make sure you are using large muscle groups (so walking is ideal) and to exercise at a pace which makes your heart work a bit harder. Simple.

If however, you are looking to improve your cardiovascular fitness you do need to be doing a bit more. The good news is that the ACSM guidelines suggest three to five sessions a week, rather than seven, and you can exercise for as little as twenty minutes. The catch being, of course, that all that exercise needs to be in one go and you have to work a little bit harder. To improve muscular fitness you need to be doing some sort of resistance work - either with weight machines, free-weights or using your body as resistance - twice a week. Do between eight and twelve repetitions of eight to ten exercises, targeting all the major muscle groups.

I believe that most people should be able to find three, twenty to sixty minute slots in their week in order to reap the enormous benefits of improving their fitness. Waking up thirty minutes earlier to grab a quick stroll before breakfast may not seem particularly appealing now, but once you start noticing your increased energy levels and the ease in which you start tackling stairs again, you may change your mind. However, sometimes life does get in the way. Some people never seem to have a moment to themselves and anyone can have an unusually hectic week. The most important thing to remember is that a little exercise is substantially better than no exercise at all. Ten minutes walking in the fresh air may not have you running a marathon but even that is better than another ten minutes sat at a desk. So, instead of worrying about how much exercise you're not fitting into your schedule, start making the most of those everyday opportunities to get moving.

We all know how much water we are meant to take in every day don't we? Two litres right? Or is it eight glasses? And coffee doesn't count does it? Does it?

When it comes to hydration, something that should be simple has become a minefield of conflicting opinions. How much we should drink, how often and in what form is a much debated issue and one that we have managed to make a lot more complicated than is necessary.
Different people need different amounts of fluid; it will depend on your body type and size and your activity level. However, our body is not dependent on us getting our fluid intake right to the exact millilitre. We have a lot of internal mechanisms that sort out water balance for us, all we need to do is make sure we are covering the basic need. With this in mind, two litres (just over 3.5 pints) is a sensible amount to aim for in a day. This can be in the form of plain water, flavoured water, soup, juice... most fluids really. The absolute exception is alcohol which is a diuretic (something that makes you lose water) and does not count towards your fluid intake. Caffeinated drinks also have a diuretic effect but it is not as pronounced, therefore, I personally would count each cup of coffee or tea as half; i.e. if you drink 400ml of tea, count it as 200ml of fluid.

The most important thing is to recognise the symptoms of dehydration. Thirst is the obvious one; you are already dehydrated if you feel thirsty. But it becomes easy to ignore our thirst when we're busy so there are other signs too. Headaches, difficulty in concentrating, hunger even though you've eaten fairly recently, slow thought processes and urine that is darker than a very pale straw colour are all signs of dehydration.

There have of course been lots of scare stories in the press about drinking too much, particularly during exercise. This can lead to the potentially fatal condition of hyponatraemia (“water poisoning”) where salt levels in our blood get too low and vital functions, like the maintenance of a regular heart beat, are disrupted. This occurs when people drink plenty of water to counteract water loss through sweating but do nothing to replace the salts also lost through sweating, thereby diluting their blood to a dangerous level. This is normally not going to be a problem when exercising for under an hour, but when it comes to longer races, like marathons and half marathons, the key to remaining safe is just to be sensible. Sports drinks which replace the lost salts are an obvious option but, unless your going to be exercising for more than two to three hours, it is perfectly safe just to drink water. While exercising take regular small amounts of water on board, rather than gulping down a litre at every drinks station. At the end of the race or event keep drinking small amounts regularly and, most importantly, eat something as soon as possible to start replacing those salts. Even if you don't fancy a three-course meal straight away, a banana or energy bar is a good start.

Taking in fluid is a vital part of our everyday life but it's one that our bodies have had millennia to get right. If it needs more fluid it will let you know, if you drink a bit too much, it will get rid of the excess for you. So if you look out for the signs and are sensible there is no need to work up a sweat over it. At least, not without replacing those salts afterwards.

For those inclined to lose a bit (or a lot) of weight there are many diets and dieting tips out there. However, the useful and valid information that could actually make a difference to the way we eat is drowning in the oceans of bad science and half-formed ideas. There are a few diet myths which I hear repeated with such alarming regularity, I consider it a duty to start busting them.

1.Eating carbs makes you fat. We take in our energy in three main forms: carbohydrate, protein and fat. The first two of these provides us with 4 calories (kcal) for every gram we eat, fat provides us with 9 calories (and for the record, alcohol provides 7 calories). So now you tell me which is most likely to make you fat. Yes, if we eat all our carbohydrates in the form of pure sugar then we may well get fat but complex carbohydrates ? your rice and grains ? are not going to make you balloon by three dress sizes overnight. If you put on top of that the fact that our brain can only use carbohydrate for energy, never fat, and the fact that you need carbohydrate in order to burn fat, you can see why nutritionists get a little ruffled at the mention of the word 'Atkins'.

2.Fat is bad. Fat is good. We need fat for a huge variety of things in the body: insulation, protection, energy reserves and stores of certain vitamins to name just a few of very many. As with all things it is moderation that is the key.

3.Being overweight means that you have slow metabolism. I can almost guarantee that, with the exception of people with a few medical conditions, if you are overweight then your metabolism is pretty impressive. Your resting metabolic rate (RMR) is basically how much energy you need to keep your body alive and working, and the more of you there is to keep alive the more calories you have to burn every minute. Similarly, the more weight you are carrying around when you exercise, the more calories you burn while doing that exercise. So that's one excuse you can't use any more...but on the plus side, it does mean that the more overweight you are the quicker you lose that weight, so get exercising and watch the transformation.

4.Eating food in the evening makes you fat. If you need energy then you need energy and it doesn't matter when you take in that energy. So, if you eat loads of calories in the morning but virtually none in the evening you will store all the calories you don't use up in the morning and then burn them off later in the day when you run out of energy. Similarly though, if you don't eat a lot in the morning and feast in the evening then you will burn off some of your energy reserves in the morning and simply replace them later when you eat again. It is not when you eat but what you eat that matters. If you take in less energy than you use then you will lose weight; if you take in more energy than you use then you will put on weight. It's a lot simpler than you think. Eat at the time that suits you and that allows you to digest your meal in comfort.

There are many other myths and horror-stories concerning diet and food. Let me know if there are any you would like me to shed some light on...