We have three sets of cones (or colour sensors) in our retinas, each of which is sensitive to a different part of the colour spectrum; the brain then constructs the rest of the spectrum by extrapolating from the relative strength of these three. In the case of purple, which occurs when the red and blue sensors but not the green ones are triggered, the brain creates a colour to fill the gap. If your brain were more objective, rather than showing you purple, it would display a patch of flickering grey with the words “system error” on it. — Rory Sutherland in Alchemy: The Surprising Power of Ideas That Don’t Make Sense (2019), section 6.2
Tag Archives: brain
If the human brain were so simple
That we could understand it,
We would be so simple
That we couldn’t. — Emerson W. Pugh (born 1929)
He Say, He Sigh, He Sow #27
“When you run and jump on rocks, your entire brain and body are at work; you stretch your back better than with yoga; every muscle in your body is involved; no two movements will be identical (unlike running in gyms); you become yourself.” — Nassim Taleb, Opacity: A Philosophical Notebook.
When we are conscious of being conscious, what are we consciousness-conscious with? If consciousness is a process in the brain, the process has become aware of itself, but how does it do so? And what purpose does consciousness-of-consciousness serve? Is it an artefact or an instrument? Is it an illusion? A sight or sound or smell is consciousness of a thing-in-itself, but that doesn’t apply here. We aren’t conscious of the thing-in-itself: the brain and its electro-chemistry. We’re conscious of the glitter on the swinging sword, but not the sword or the swing.
We can also be conscious of being conscious of being conscious, but beyond that my head begins to spin. Which brings me to an interesting reminder of how long the puzzle of consciousness has existed in its present form: how do we get from matter to mind? As far as I can see, science understands the material substrate of consciousness – the brain – in greater and greater detail, but is utterly unable to explain how objective matter becomes subjective consciousness. We have not moved an inch towards understanding how quanta become qualia since this was published in 1871:
Were our minds and senses so expanded, strengthened, and illuminated, as to enable us to see and feel the very molecules of the brain; were we capable of following all their motions, all their groupings, all their electric discharges, if such there be; and were we intimately acquainted with the corresponding states of thought and feeling, we should be as far as ever from the solution of the problem, “How are these physical processes connected with the facts of consciousness?” The chasm between the two classes of phenomena would still remain intellectually impassable.
Let the consciousness of love, for example, be associated with a right-handed spiral motion of the molecules of the brain, and the consciousness of hate with a left-handed spiral motion. We should then know, when we love, that the motion is in one direction, and, when we hate, that the motion is in the other; but the “Why?” would remain as unanswerable as before. — John Tyndall, Fragments of Science (1871), viâ Rational Buddhism.
• Double Bubble
• The Brain in Pain
• The Brain in Train
• This Mortal Doyle
The Sound of Silex
Some of the most beautiful patterns in nature arise from the interaction of three very simple things: sand and water, sand and air. Sculptrix Sabulorum, a side-project of the Exeter band Slow Exploding Gulls, are an attempt to do with sound what nature does with sand: turn simple ingredients into beautiful patterns. Here are extracts from an interview and review in the Plymouth fanzine EarHax:
Hector Anderton: OK. The obvious first. Sculptrix Sabulorum. What does it mean and why did you choose it?
Joe Corvin: It’s Latin and literally means “Sculptress of the Sands”. We chose it, well, because we thought it looked and sounded good. Good but mysterious.
Hector Anderton: And who is the sculptress? The sea?
Joe Corvin: Well, the sculptress is Mother Nature, in the fullest sense, but she uses the sea. The wind. Gravity. Simple things, but put them together with sand and interesting things happen.
Cath Orne: Which we wanted to explore, but we didn’t think S.E.G. [Slow Exploding Gulls] was the way to explore them.
Hector Anderton: But hadn’t you done that in Silica?
Joe Corvin: We’d started to, but Silica hadn’t exhausted the theme. Of sand, I mean. It’s something I’d always been interested in, but with S.E.G. we tend to go with the organic side of the sea, with sea life.
Hector Anderton: Whereas sand is inorganic?
Joe Corvin: Exactly. Silica was a bit of a departure for us, in that respect. It was as though we were walking down a corridor and we opened a door in passing and thought, yeah, that room looks interesting.
Cath Orne: So we’ll come back and have a proper look later.
Joe Corvin: Yeah. Under a new name. Which we’ve done. Hence, Sculptrix Sabulorum.
Extract © EarHax (1992)
Skulsonik, Sculptrix Sabulorum (Umbra Mundi 1995)
Macca to Madonna: “Listen to the music playing in your head.” In fact, we never do anything else. We don’t experience the world: we experience a sensory simulacrum of the world. Light or sound-waves or chemicals floating in the air stimulate the nerves in our eyes or ears or nose and the brain turns the resultant stream of electrical pulses into sight or sound or smell.
But it does more than that: it covers up the cracks. Raw nerve-stuff is not smooth and polished sensation. We have blind-spots, but the brain edits them out. Only a small part of our visual field is actually in clear focus, but we think otherwise. If we could see raw nerve-stuff, it would be a blurry, fuzzy mess.
The same is true of hearing. And Skulsonik is an attempt to record raw nerve-stuff: to capture not sound out there, but sound in here – the music playing in your head. Sculptrix Sabulorum have set out to answer a simple question: “What does music really sound like?” Or rather: what does music cerebrally sound like? What does it sound like in your head?
Extract © EarHax (1995)
Previously pre-posted (please peruse):
• Mental Marine Music – Slow Exploding Gulls
This Mortal Doyle
Challenger chopped and changed. That is to say, in one important respect, Arthur Conan Doyle’s character Professor Challenger lacked continuity. His philosophical views weren’t consistent. At one time he espoused materialism, at another he opposed it. He espoused it in “The Land of Mist” (1927):
“Don’t tell me, Daddy, that you with all your complex brain and wonderful self are a thing with no more life hereafter than a broken clock!”
“Four buckets of water and a bagful of salts,” said Challenger as he smilingly detached his daughter’s grip. “That’s your daddy, my lass, and you may as well reconcile your mind to it.”
But earlier, in “The Poison Belt” (1913), he had opposed it:
“No, Summerlee, I will have none of your materialism, for I, at least, am too great a thing to end in mere physical constituents, a packet of salts and three bucketfuls of water. Here ― here” ― and he beat his great head with his huge, hairy fist ― “there is something which uses matter, but is not of it ― something which might destroy death, but which death can never destroy.”
That story was published just over a century ago, but Challenger’s boast has not been vindicated in the meantime. So far as science can see, matter rules mind, not vice versa. Conan Doyle thought the same as the earlier Challenger, but Conan Doyle’s rich and teeming brain seems to have ended in “mere physical constituents”. To all appearances, when the organization of his brain broke down, so did his consciousness. And that concluded the cycle described by A.E. Housman in “Poem XXXII” of A Shropshire Lad (1896):
From far, from eve and morning
And yon twelve-winded sky,
The stuff of life to knit me
Blew hither: here am I.
Now – for a breath I tarry
Nor yet disperse apart –
Take my hand quick and tell me,
What have you in your heart.
Speak now, and I will answer;
How shall I help you, say;
Ere to the wind’s twelve quarters
I take my endless way. (ASL, XXXII)
Continue reading This Mortal Doyle…
The Brain in Train
I feel odd when I consider this possibility: that all my thoughts are strictly determined, no more under my control than a straw in a gale or a stone in an avalanche. It seems paradoxical to have strictly determined thoughts about strictly determined thoughts. But is it? And is strict determinism fatal for finding the truth? I don’t think so. In fact, I think that strict determinism is essential for truth. But irrelevant associations get in the way of our understanding this. If our thoughts are determined, they seem like automatic trains running on rigid tracks. We might want to go to the station marked “Truth”, but if the switches are set wrong, the train will never get there. Or it will thunder through and never stop.
Continue reading The Brain in Train…
Electrify Your Eyes
The Spark of Life: Electricity in the Human Body, Frances Ashcroft (Penguin 2013)
“Electricity in the Human Body” is the subtitle of this book. Make that the goat, frog, eel, shark, torpedo-ray, snake, platypus, spiny anteater, sooty shearwater and fruit-fly body too. And if Venus flytraps, maize and algae have bodies, throw them in next. Frances Ashcroft gives you a bargeload of buzz for your buck, a shedload of shock for your shekel: The Spark of Life describes the use of electricity by many different forms of life. But it discusses death a lot too, from lightning-strikes and electric chairs to heart-attacks and toxicology. Poisons can be a cheap and highly effective way of interfering with the electro-chemistry of the body:
The importance of sodium and potassium channels in generating the nerve impulse is demonstrated by the fact that a vast array of poisons from spiders, shellfish, sea anemones, frogs, snakes, scorpions and many other exotic creatures interact with these channels and thereby modify the function of nerve and muscle. … The tetrodotoxin contained in the liver and other tissues of this fish [the fugu or puffer-fish, Takifugu spp., Lagocephalus spp., etc] is a potent blocker of the sodium channels found in your nerves and skeletal muscles. It causes numbness and tingling of the lips and mouth within as little as thirty minutes … This sensation of “pins and needles” spreads rapidly to the face and neck, moves onto the fingers and toes, and is then followed by gradual paralysis of the skeletal muscles … Ultimately the respiratory muscles are paralysed, which can be fatal. The heart is not affected, as it has a different kind of sodium channel that is far less sensitive to tetrodotoxin. The toxin is also unable to cross the blood-brain barrier so that, rather horrifyingly, although unable to move and near death, the patient remains conscious. (ch. 3, “Acting on Impulse”, pp. 69-70)
In short, fugu-poisoning is the opposite of electrocution: it’s the absence rather than the excess of electricity that kills its victims. Those “channels” are a reminder that electro-chemistry could also be called electro-mechanics: unlike an electricity-filled computer, an electricity-filled body has moving parts – and in more ways than one. Our muscles move because ions move in and out of our cells. This means that a body has to be wet inside, not dry like a computer, but it’s easy to imagine a human brain controlling a robotic body. But would a brain still be conscious if it became metal-and-plastic too? Perhaps a brain has to be both soggy and sparky to be conscious.
The electrical nature of the brain certainly seems important, though that may be a superstitious conclusion. Electricity is a mysterious phenomenon and so is consciousness, so they seem to go together well. Ashcroft writes a lot about the sense-organs and the data they supply to the brain, but like all scientists she cannot explain how those data are turned into conscious experience as the maths-engine of the brain applies its neuro-functions and neuro-algorithms. However, she does suggest ways in which our consciousness might be expanded in future. Humans have colour vision, based on the three types of cone-cells in our eyes:
Most mammals, such as cats and dogs, have only two types of cone photopigment and so see only a limited range of colour … Other animals live in a world entirely without colour. But humans should not be too complacent, for we are far from having the best colour vision in the animal world and lag far behind the mantis shrimp, which enjoys ten or more different visual pigments. Even tropical fish possess four or five types of cones. (ch. 9, “The Doors of Perception”, pg. 199)
Bio-engineering may one day sharpen and extend all our senses, from sight and hearing to touch, taste and smell. It may also give us new senses, like the ability to form sound-pictures like bats and detect infra-red like pit-vipers. And why not X-rays and radio-waves too? It’s an exciting prospect, but in a sense it won’t be anything new: our new senses, like our old ones, will depend on nerve-impulses and the way they’re mashed and mathed in that handful of “electrified clay” known as the brain.
“Electrified clay” is Shelley’s phrase: like his wife Mary, he was fascinated by the early electric experiments of the Italian scientists Luigi Galvani and Alessandro Volta. Mary turned her fascination into a book called Frankenstein (1818) and her invention is part of the scientific history in this book. The story of bio-electricity is still going strong: there are electric mysteries in all kinds of bodies waiting to be solved. Maybe consciousness is one of them. And if science proves unable to crack consciousness, it’s certainly able to expand it. Reading this book is one way to experience the mind-expanding powers of science, but seeing like a mantis shrimp would be good too.
Neuclid on the Block
How many blows does it take to demolish a wall with a hammer? It depends on the wall and the hammer, of course. If the wall is reality and the hammer is mathematics, you can do it in three blows, like this:
α’. Σημεῖόν ἐστιν, οὗ μέρος οὐθέν.
β’. Γραμμὴ δὲ μῆκος ἀπλατές.
γ’. Γραμμῆς δὲ πέρατα σημεῖα.
1. A point is that of which there is no part.
2. A line is a length without breadth.
3. The extremities of a line are points.
That is the astonishing, world-shattering opening in one of the strangest – and sanest – books ever written. It’s twenty-three centuries old, was written by an Alexandrian mathematician called Euclid (fl. 300 B.C.), and has been pored over by everyone from Abraham Lincoln to Bertrand Russell by way of Edna St. Vincent Millay. Its title is highly appropriate: Στοιχεῖα, or Elements. Physical reality is composed of chemical elements; mathematical reality is composed of logical elements. The second reality is much bigger – infinitely bigger, in fact. In his Elements, Euclid slipped the bonds of time, space and matter by demolishing the walls of reality with a mathematical hammer and escaping into a world of pure abstraction.
• Continue reading Neuclid on the Block
Methods of Mutagenesis
“However, many of the methods neuroscientists use to alter gene expression are not used by parasites (e.g. X-ray mutagenesis).” — a funny line in an interesting article: “Parasites: evolution’s neurobiologists” (2012).