Long ago, when I was a high school student in America, I remember a biology teacher had taught me that all the chemicals that make up a human body could be bought at a hardware store for $ 5 or something like that.
I remember that I was surprised at the idea that you could make a messy and pimpy thing like me for almost nothing.
It was such a spectacularly humble revelation that it has stayed with me all those years. The question is: was it true? Are we really worth so little?
Bill Bryson is pictured above with an anatomy model. As a boy, the author was told that all the chemicals needed to make a human body would only cost $ 5
Many authorities have tried at different times to calculate how much it would cost in materials to build a person.
Perhaps the most extensive attempt in recent years was made by the Royal Society of Chemistry (RSC) when, as part of the Cambridge Science Festival 2013, it calculated how much it would cost to collect all the elements needed to actor Benedict Cumberbatch build.
(Cumberbatch was the festival's guest director that year and was, preferably, a normal-sized person.)
According to RSC calculations, 59 elements are needed to construct a person. Six of these – carbon, oxygen, hydrogen, nitrogen, calcium and phosphorus – account for 99.1 percent of what we make, but the rest are somewhat unexpected.
For your brain, the world is just a stream of electrical pulses, such as Morse code faucets. And from this bare and neutral information that it creates for you – literally creates – a lively, three-dimensional, sensually attractive universe
Who would have thought that we would be incomplete without some molybdenum in us, or vanadium, manganese, tin and copper?
All in all, according to the RSC investigation, the full cost of building a new person would be a very accurate £ 96,546.79. Labor and VAT would, of course, further increase costs.
You'd probably be lucky enough to take a Benedict Cumberbatch home for much less than £ 200,000 – not a huge fortune, all in all, but clearly not the meager few dollars my high school teacher suggested.
But of course it hardly matters. No matter what you pay or how carefully you assemble the materials, you are not going to create people.
You could bring together all the smartest people who are now alive or have ever lived and give them the full sum of human knowledge and they couldn't make a cell between them, let alone a Benedict Cumberbatch replica.
That is without doubt the most amazing thing about us – that we are just a collection of inert components, the same things that you would find in a pile of earth.
The only special thing about the elements that make you is that they make you. That is the miracle of life.
It is 80% water – the rest is fat and protein
Your brain only needs about 400 calories a day – about the same as you get in a blueberry muffin. Try running your laptop on a muffin for 24 hours and see how far you get
The most special thing in the universe is in your head. You could travel through every inch of space and most likely find nothing as great and complex and highly functional as the three pounds of spongy mass between your ears.
For an object of pure wonder, the human brain is extremely unpleasant. It is primarily 75 to 80 percent water, the rest is usually divided between fat and protein.
Quite astonishing that three of such everyday fabrics can come together in a way that allows our thoughts and memories and vision and aesthetic appreciation and everything else.
The great paradox of the brain is that everything you know about the world is offered to you by an organ that has never seen that world itself.
The brain exists in silence and darkness, like a dungeon with a dungeon. It has no pain receptors – literally no feelings. It has never felt warm sunshine or a gentle breeze.
For your brain, the world is just a stream of electrical pulses, such as Morse code faucets. And from this bare and neutral information that it creates for you – literally creates – a vibrant, three-dimensional, sensually attractive universe.
Your brain is you. Everything else is just plumbing and scaffolding.
Just sit quietly, do nothing at all, your brain rotates through more information in 30 seconds than the Hubble Space Telescope has processed in 30 years.
Considering how exhaustively the brain has been studied, and for how long, it is remarkable how many basic things we still do not know or at least cannot agree. Like what exactly is consciousness? Or what exactly is a thought? (File photo)
A piece of cortex of a cubic millimeter – about the size of a grain of sand – can hold 2,000 terabytes of information, enough to store all the movies ever made, including trailers, or about 1.2 billion copies of an average book.
All in all, the human brain is estimated to be in the order of 200 exabytes of information, roughly equivalent to "the entire digital content of today's world," according to Nature Neuroscience.
If that is not the most extraordinary thing in the universe, we must surely find some miracles.
The brain is often depicted as a hungry organ. It only accounts for two percent of our body weight, but consumes 20 percent of our energy.
With newborn babies it's no less than 65 percent of their energy. That is partly why babies & # 39; s sleep all the time – their growing brain depletes them.
But it is also incredibly efficient. Your brain only needs about 400 calories a day – about the same as you get in a blueberry muffin.
Try running your laptop on a muffin for 24 hours and see how far you get.
A section the size of a peanut determines your destination
As the most complex of our organs, the brain – not surprisingly – has more named features and landmarks than any other part of the body, but essentially it divides into three parts.
At the top, literally and figuratively, is the cerebrum, which fills most of the skull vault and that is what we normally think of when we think of "the brain." The cerebrum (from the Latin word for & # 39; brain & # 39;) is the seat of all our higher functions.
It is divided into two halves of the brain, each of which mainly relates to one side of the body, but for unknown reasons the vast majority of the wiring is crossed, so that the right side of the cerebrum controls the left side of the body and vice versa.
A piece of cortex a cubic millimeter in size – about the size of a grain of sand – can hold 2,000 terabytes of information, enough to store all the movies ever made, including trailers, or about 1.2 billion copies of an average book ( file photo))
Each hemisphere of the large brain is further divided into four lobes – frontal, parietal, temporal and occipital – each broadly specialized in certain functions.
The frontal lobe is the seat of the higher functions of the brain – reasoning, thinking, problem solving, emotional control, and so on. It is the part that is responsible for the personality, for who we are.
Below the cerebrum, at the very back of the head, approximately where it touches the neck, is the cerebellum (Latin for & # 39; small brain & # 39;). Although the cerebellum occupies only ten percent of the cranial cavity, it has more than half of the neurons or nerve cells of the brain.
It has many neurons, not because it thinks a lot, but because it controls balance and complex movements, and that requires an abundance of wiring.
At the base of the brain, descending from it like a lift shaft that connects the brain to the spine and the body behind it, is the oldest part of the brain, the brainstem. It is the seat of our more basic operations: sleeping, breathing, keeping the heart going.
The brain stem does not receive much attention, but it is so central to our existence that brain stem death in the UK is the fundamental measure of human death.
The frontal lobe is the seat of the higher functions of the brain – reasoning, thinking, problem solving, emotional control, and so on. It is the part that is responsible for the personality, for who we are (file photo)
Scattered through the brain, like nuts in a fruit cake, are much smaller structures: hypothalamus, amygdala, hippocampus and others, collectively known as the limbic system (from the Latin limbus, which means peripheral).
It's easy to go a lifetime without hearing a word about one of these components unless they go wrong.
The basal ganglia, for example, play an important role in movement, language and thinking, but it is only when they degenerate and lead to Parkinson's disease that they normally focus attention on themselves.
The most important part of the limbic system is a small powerhouse, the hypothalamus. Although only the size of a peanut and barely a tenth of an ounce weighs, it controls much of the body's most important chemistry.
It regulates sexual function, regulates hunger and thirst, controls blood sugar and salts, determines when you should sleep. It may even play a role in how slowly or rapidly we age. A large part of your success or failure as a human depends on this little thing in the middle of your head.
The hippocampus is central to the recording of memories. (The name comes from the Greek for "sea horse" because of the alleged similarity with that creature.)
The amygdala (Greek for & # 39; almond & # 39;) specializes in dealing with intense and stressful emotions – fear, anger, fear, all kinds of phobias.
People whose amygdalae have been destroyed are literally left fearless and often cannot even recognize fear in others.
Why teenage brains are so different
It takes a long time for the brain to fully form. The wiring in a teenager's brain is only about 80 percent complete (which may not be a big surprise to their parents).
Although most of brain growth takes place in the first two years and is 95 percent complete by the age of ten, the synapses – the small spaces between nerve cell ends – are not fully wired until a young person in his or her mid to late 20s. That means that the teenage years effectively extend into adulthood.
In the meantime, the person in question will almost certainly display more impulsive, less reflective behavior than his elderly, and will also be more sensitive to the effects of alcohol.
"The teenage brain is not just an adult brain with fewer kilometers," Frances E. Jensen, a neurology professor, told Harvard Magazine in 2008. It is rather a completely different brain.
The nucleus accumbens, a region of the forebrain associated with pleasure, grows to its largest size in the teenage years. At the same time, the body produces more dopamine, the neurotransmitter that transmits pleasure, than ever before.
That is why the sensations you feel as a teenager are more intense than at any other time in life. But it also means that seeking pleasure is a professional risk for teenagers.
The leading cause of deaths among teenagers is accidents – and the leading cause of accidents is simply being with other teenagers.
For example, if there is more than one teenager in a car, the risk of an accident multiplies by 400 percent.
Considering how exhaustively the brain has been studied, and for how long, it is remarkable how many basic things we still do not know or at least cannot agree. Like what exactly consciousness is? Or what exactly is a thought?
It is not something that you can catch in a jar or put on a microscopic slide, and yet a thought is clearly a real and definitive thing.
Thinking is our most vital and wonderful talent, but in a deep physiological sense we don't really know what thinking is.
About the same can be said about the memory. We know a lot about how memories are collected and how and where they are stored, but we don't know why we don't keep some and others. It clearly has little to do with actual value or utility.
I can remember the entire line-up of the 1964 St. Louis Cardinals baseball team – something that has not been important to me since 1964 and was actually not very useful at the time – and yet I can remember my own cell phone number don't remember where I parked my car or one of the many other things that are undoubtedly more urgent and necessary.
So there is still a huge amount that we still have to learn and many things that we may never learn. But some of the things that we know are just as great as the things we don't know. Consider how we see – or, to put it more precisely, how the brain tells us what we see. Take a look around you now. The eyes send one hundred billion signals to the brain every second. But that is only part of the story.
It used to be thought that every experience is permanently stored as memory somewhere in the brain, but that most of it is locked up outside our power of immediate recall (file photo)
When you see something, only about ten percent of the information comes from the optic nerve. Other parts of your brain have to deconstruct the signals – recognize faces, interpret movements, identify danger. In other words, the majority of seeing is not receiving visual images, it makes sense.
For each visual input, it takes a small but noticeable amount of time – about a fifth of a second – for the information to travel through the optic nerves and to the brain to be processed and interpreted.
A fifth of a second is not a trivial period of time when a fast response is required, for example, to step back from an oncoming car, or to prevent a blow to the head.
To help us cope better with this fractional delay, the brain really does something extraordinary: it continuously predicts what the world will look like in a fifth of a second from now, and that's what it gives us now.
That means we never see the world as it is right now, but rather that it will be a fraction of a moment in the future. We spend our entire lives, in other words, we live in a world that does not yet fully exist.
The brain is deceiving you and is very unreliable
The brain deceives you in many ways for your own good. Sound and light reach you at very different speeds – a phenomenon that we experience every time we hear a plane pass by and look up to find the sound coming from one part of the sky and a plane moving silently through another part.
In the more immediate world around you, your brain normally clears away these differences. What you see is not what is, but what your brain tells you it is, and that's not the same at all.
Consider a bar of soap. Have you ever noticed that soap foam is always white, regardless of the color of the soap? That is not because the soap changes color somehow when it is moistened and rubbed.
Molecularly it is exactly as it was before. It's just that the foam reflects the light in a different way.
You get the same effect with crashing waves on a beach – greenish blue water, white foam – and many other phenomena.
That is because color is not a fixed reality, but a perception. Your brain does all these things for you because it is designed to help you in every way possible. But paradoxically, it is also remarkably unreliable.
A few years ago, Elizabeth Loftus, a psychologist at the University of California, Irvine, discovered that it is possible by suggestion to completely implant false memories into people's heads – to convince them that they were traumatically lost in a shopping mall when they were small or were cuddled by Bugs Bunny at Disneyland – although these things never happened. (First, Bugs Bunny is not a Disney character and has never been to Disneyland.)
She showed people pictures of themselves as a child in which the image was manipulated to make them look like they were in a hot air balloon, and often the subjects suddenly remembered the experience and described it enthusiastically, although it certainly was known it never happened.
Now you would think that you could never be so suggestive, and you would probably be right – only about a third of people are so gullible – but other evidence shows that sometimes we even completely remember even the most vivid events.
In 2001, immediately after the 9/11 disaster at the New York World Trade Center, University of Illinois psychologists took detailed statements from 700 people about where they were and what they were doing when they heard about the event.
A year later, the psychologists asked the same questions to the same people and found that nearly half now contradicted themselves in an important way – relocating themselves when they heard of the disaster, believing they'd seen it on TV when, in them had even heard it on the radio and so on – but without realizing that their memories had changed.
Man who has memorized 27 card games
Short-term memory is very short – no more than half a minute for things like addresses and phone numbers. (If you can still remember something after half a minute, it's technically no longer a short-term memory. It's a long-term one.)
The short-term memory of most people is pretty nasty. Six random words or numbers are just about anything that most of us can reliably keep for more than a few moments.
On the other hand, we can hardly train our memories to perform the most extraordinary stunts. Every year the United States has a national memory championship and the performances that are performed there are truly amazing.
One man remembered the series of 27 randomly shuffled card games in 30 minutes. Most memory champions are not spectacularly intelligent (file photo)
One memory champion could remember 4,140 random digits after watching it for only 30 minutes.
Another could remember the series of 27 randomly shuffled card games in the same period.
Still another can remember one card game after 32 seconds of study.
These may not be the most valuable use of the human mind, but they are certainly demonstrations of its incredible powers.
Most memory champions aren't spectacularly intelligent by the way.
They are just motivated enough to train their memories to do some extraordinary tricks.
(I, for my part, vividly remember how I saw the events live on television in New Hampshire, where we were then living, with two of my children, to hear later that one of those children was in England at the time.)
The result is that memory is not a fixed and permanent record, like a document in a file cabinet.
As Loftus told an interviewer in 2013: "It looks a bit like a Wikipedia page. You can go in there and change it, and other people too. & # 39;
Fundamental memories come in two main varieties: declarative and procedural. Explanatory memory is the kind that you can articulate – the names of capitals, your date of birth and everything else that you know as fact.
Procedural memory describes the things that you know and understand, but that you cannot express so easily: how to swim, drive a car, peel an orange.
It used to be thought that every experience is permanently stored as memory somewhere in the brain, but that most of it is locked away from our power of immediate memory.
The idea originated primarily from a series of experiments in Canada from the 1930s to the 1950s by neurosurgeon Wilder Penfield.
While performing surgical procedures at the Montreal Neurological Institute, Penfield discovered that when he touched a probe on the brains of patients, it often evoked powerful sensations: lively scents from childhood, feelings of euphoria, sometimes a memory of a forgotten scene from all over early life.
It was concluded that the brain records and stores every conscious event in our lives, no matter how trivial. However, it is now thought that the stimulation mainly gave the feeling of memory and that what the patients experienced was more a hallucination than a recalled event.
What is certainly true is that we retain much more than we can easily remember. You may not remember much of a neighborhood where you lived when you were a kid, but if you went back and walked around it, you would almost certainly remember very special details that you hadn't thought of for years.
With enough time and prompt we would probably all be surprised at how much we have stored in us.
Ironically, the person from whom we learned a lot about what we know about memory was a man who himself had little of it.
Henry Molaison was a handsome young man of 27 in Connecticut who suffered from paralyzing episodes of epilepsy.
In 1953, a surgeon, William Scoville, inspired by Wilder Penfield's efforts in Canada, drilled into Molaison's head and removed half of the hippocampus on each side of his brain.
The procedure significantly reduced Molaison's attacks (although it did not completely eliminate them), but at the expense of the tragic cost of depriving him of the ability to form new memories.
Molaison could remember events from his distant past, but someone who left the room would be immediately forgotten.
Even a psychiatrist who saw him almost daily for years was a new person to him every time she came through the door. Occasionally and mysteriously, Molaison could only record a few memories.
He remembered that John Glenn was an astronaut and Lee Harvey Oswald a contract killer (though he couldn't remember who killed Oswald) and heard the address and layout of his new house when he moved. But otherwise he was locked up in an eternal present.
The plight of poor Henry Molaison was the first scientific indication that the hippocampus plays a central role in recording memories.
But what Molaison scientists learned was not so much about how memory works, but how hard it is to understand how it works.
Doctor lobotomized JFK & # 39; s sister Rosemary
Despite all its miracles, the brain is a remarkable non-demonstrative organ. The heart is pumping, the lungs are being inflated and deflated, the intestines are still wrinkling and gargling, but the brain is just blancmange-like and gives nothing away.
It is therefore not surprising that our understanding of how the brain functions was slow and largely unintended.
One of the major events in early neuroscience took place in the Vermont countryside in 1848, when a young railroad builder named Phineas Gage was packing dynamite into a rock and prematurely exploding and a two-foot pusher through his left cheek and out of the top of his go before it clattered back to earth about 50 feet away.
The rod removed a perfect brain core with a diameter of approximately one centimeter. Miraculously, Gage survived and does not even seem to have lost consciousness, although he lost his left eye and his personality was forever transformed.
Previously happy-go-lucky and popular, he was now moody, argumentative and committed to profane outbursts.
As often happens with people with frontal lobe damage, Gage had no insight into his condition and did not understand that he had changed.
The Gage accident was the first evidence that physical brain damage could transform personality, but in the following decades others noted that when tumors destroyed or collided parts of the frontal lobes, the victims sometimes became remarkably serene and calm.
In the 1880s, a Swiss physician named Gottlieb Burckhardt surgically removed 18 grams of brains from a disturbed woman who changed her (in his own words) from & # 39; a dangerous and excitedly demented person to a quiet / demented & # 39 ;.
He tried the trial on five more patients, but three died and two developed epilepsy, so he gave up.
Fifty years later, in Portugal, a professor of neurology at the University of Lisbon, Egas Moniz decided to try again, and experimentally cut the frontal lobes of schizophrenics to see if that could calm their troubled mind. It was the invention of the frontal lobotomy.
In the US, a physician named Walter Jackson Freeman heard of the Moniz procedure and became his most enthusiastic acolyte. Over a period of nearly 40 years, Freeman traveled the country with lobotomies on almost everyone who was presented to him. During a tour, he lobotomized 225 people in 12 days.
Some of his patients were as young as four years old. He operated on people with phobias, on drunks picked up from the street, on people convicted of homosexual acts – on everyone, in short, with almost any form of perceived mental or social aberration.
Freeman's method was so quick and brutal that other doctors shrank. Hij stopte een standaard huishoudelijke ijspriem in de hersenen door de oogkas, tikte ermee door het schedelbot met een hamer en draaide het vervolgens krachtig om neurale verbindingen te verbreken.
De procedure was zo grof dat een ervaren neuroloog van de universiteit van New York flauwviel tijdens het kijken naar een Freeman-operatie.
Gedurende een periode van bijna 40 jaar reisde Freeman (boven) het land af met lobotomieën bij bijna iedereen die hem werd voorgelegd. Tijdens een rondleiding lobotomiseerde hij 225 mensen in 12 dagen
Maar het ging snel: patiënten konden over het algemeen binnen een uur naar huis gaan. Het was deze snelheid en eenvoud die velen in de medische gemeenschap verblindde.
Freeman was buitengewoon nonchalant in zijn benadering. Hij opereerde zonder handschoenen of een chirurgisch masker, meestal in straatkleding.
De methode veroorzaakte geen littekens, maar betekende ook dat hij zonder enige zekerheid opereerde over welke mentale capaciteiten hij vernietigde.
Wat misschien wel het meest opmerkelijk is, is dat Freeman een psychiater was zonder chirurgische certificering, een feit dat veel andere artsen afschuwde.
Ongeveer tweederde van de proefpersonen van Freeman ontving geen voordeel van de procedure of was slechter af. Twee procent stierf.
Zijn meest beruchte mislukking was Rosemary Kennedy, zus van de toekomstige president. In 1941 was ze 23 jaar oud, een levendig en aantrekkelijk meisje, maar eigenzinnig en met een neiging tot stemmingswisselingen.
Ze had ook wat leerproblemen. Haar vader, geïrriteerd door haar eigenzinnigheid, liet haar lobotomiseren door Freeman zonder zijn vrouw te raadplegen.
De lobotomie vernietigde in wezen Rosemary. Ze bracht de volgende 64 jaar door in een verzorgingshuis in het Midwesten, niet in staat om te spreken, incontinent en verstoken van persoonlijkheid.
Freeman bleef lobotomieën uitvoeren tot ver in zijn jaren '70 voordat hij in 1967 met pensioen ging. Maar de effecten die hij en anderen in hun kielzog achterlieten, duurden jaren.
Ik kan hier met enige ervaring spreken. Begin jaren zeventig werkte ik twee jaar in een psychiatrisch ziekenhuis buiten Londen, waar een afdeling grotendeels werd bezet door mensen die in de jaren veertig en vijftig waren gelobotomiseerd. Het waren, bijna zonder uitzondering, gehoorzame, levenloze granaten.
In surely its most questionable entry, the 2001 Oxford Companion To The Body says: ‘For many people the term “lobotomy” conjures up images of disturbed beings whose brains have been damaged or mutilated extensively, leaving them at best in a vegetative state without a personality or feelings. This was never true.’ Actually, it was.
© Bill Bryson, 2019
Abridged extract from The Body: A Guide For Occupants, by Bill Bryson, which is published by Doubleday on October 3, priced £25.
Offer price £20 (20 per cent discount) until September 30. To pre-order, call 01603 648155 or go to mailshop.co.uk.
See Bill Bryson live on stage in a new theatre show. For information and tickets, go to lateralevents.com.
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