The Idea of the Brain
Speaker: Professor Matthew Cobb
Thursday, 22 July 2021
On Thursday 15th July, the Todmorden U3A guest speaker was Professor Matthew Cobb, his subject: 'The Idea of the Brain'. He has previously presented this talk to the Royal Institution in London, and he is Professor of Zoology at Manchester University. He started by telling us that, for most of history, people believed that thinking was done with the heart. This belief is in no small part due to the way we have spoken over the years. One of Matthews illustrations brought this home with examples such as 'heartfelt', 'heart of stone' and 'take it to heart'. The idea of these feelings coming from somewhere else didn't take hold until relatively recently. The expressions which mentioned the heart being the source of feelings and emotions persisted because they do affect the heart. It beats faster when we are afraid or upset, and disappointment, or sympathy, seem to cause genuine feelings coming from the heart.
The ancient Greeks thought about this, Aristotle saying that the heart was the centre of thought, but in 5 BCE three other philosophers argued that the mind was in the brain although they didn't have any evidence.
In in the first or second century CE (AD in old money) Galen, a philosopher and surgeon, demonstrated that a pig's heart could be stopped but the pig remained conscious. However, pressing down on its brain caused the pig to be unconscious.
Matthew told us that there was no actual event, or date, when people realised that that it was the brain, and not the heart, doing all the thinking and deciding. However, there is evidence that from the fourteenth century, the idea that the brain was involved was gathering some momentum. Part of Shakespeare's 'Merchant of Venice' asks 'Tell me where is fancie (imagination) bred – in the heart or in the head?'.
In 1775 Joseph Priestley, a Yorkshire born chemist and scientist, said that there was no evidence of anyone being able to think after their brain had been destroyed, but that there was evidence of thinking being impeded if the brain had become damaged. Matthew stressed that there was no definitive experiment that proved this, but the conclusions were reached based on anatomy and what was already known.
By the end of the century, this theory began to take hold, Matthew describing this process as 'a slow accumulation of certainty' . Despite the change in opinion of the brain v. heart debate or argument, there was little in the way of evidence or breakthrough let alone proof, of how the brain actually worked.
He told us about an experiment carried out in the mid seventeenth century. By this time, static electricity had been discovered, and could be harnessed. Four hundred monks took part in an experiment which involved them holding hands and one of them (perhaps, but not certainly, a volunteer), received a volt or two from the source and it passed through the rest of the line and made them jump. This preceded another, more ghoulish, test in 1804, after the pleasingly named Alessandro Volta played a large part in inventing the batteries that we still can't always find when we need them today, basing his findings after studying the shock produced by electric eels.
This enabled further research into the stimulation of bodies, including those of the deceased. This particular test was carried out on the body of a very recently executed murderer, which showed that by applying contact with the battery the dead body moved and reacted. It was conducted by a man called Goivanni Aldini, whose uncle also had an involvement in the development etc. of electricity – Signor Luigi Galvani. The tests were observed by other eminent scientists who were understandably alarmed when the dead body's arms and legs moved, and the eyes opened and closed during the experiment.
This led to demonstrations of this phenomena being attended by the general public, where the cadavers of animals, rather than humans, had electricity applied to them – resulting in limbs moving. One of these displays took place at the Royal Institution and, it is thought, was witnessed by a young lady called Mary. A few years later, her interests developed into writing and she had married a poet called Percy Bysshe Shelley. Did she remember the experiment when she created Frankenstein?
Electricity led to the invention of the UK's telegraph system, based in London, and some people suggested this was how the brain worked. An inventor named Albert Smee said that 'Whatever is seen, or heard, or felt, is telegraphed to the brain'. Mr Smee also produced diagrams which showed the flow of information to and from the brain, from the eyes, ears and nose of people and animals. Matthew said that the main achievement of the diagrams showed that there was actual logical thinking about how the brain might work, unfortunately though, it doesn't work like that. He added that, around the same time the 'science' of phrenology, perhaps better known as 'feeling the bumps' was being promoted.
Although phrenology was a 'made up' science, the maps shown on the model heads used do have some relevance to what is known about the brain. The part of Matthew's brain used for his delivery of the talk is called 'Broca's area' and is unique to humans, and is affected by strokes. Broca's area is part of a 'map' of the brain showing, to an extent, which part affects different areas of the body and mind. These were researched using live monkeys, and stimulating various areas of the brain and noting the results.
Suggestions about how the brain might work include it being like a telephone exchange and a clockwork ladybird that managed to turn back each time it reached the edge of a surface. Matthew said that the actual processes have never been fully established.
In the 1940's, Professor Kenneth Craik put forward a view about 'the fundamental feature of neural machinery – its power to parallel or model external events'. Matthew said that this was the accepted view of what the brain does. He said that neurons, carried by synapses, in our bodies are much more sophisticated than any computer system. Each synapse contains dozens of neurons, as well as five and half thousand proteins.
Matthew showed a clip of just 45 proteins within a synapse – a bewildering series of movements and journeys , visible in the clip shown in thousandths of one second.
More mindboggling figures followed when Matthew referred to images of the brain that we sometimes see on medical TV programmes. The areas highlighted do actually show what part of the brain is doing something – but not what it's doing. The area, known as a voxel, is likely to contain five and a half million neurons and up to fifty five billion synapses.
Matthew concluded with his thoughts on how we might establish and prove how brains actually work – by concentrating on creatures with the smallest brains, and which carry out the fewest functions.
A vote of thanks followed, for an absorbing hour of history and well explained science leaving us secure in the knowledge that, even if we don't know everything about how our brains work, no-one else does either.
The next Todmorden U3A Monthly Members Meeting by Zoom will be on Thursday 19th August 2021 at 1.45 p.m. open to all fully paid-up members. Our speaker for August will be Colin Philpott taking about 'Secret Wartime Britain'
Not yet a member? You can attend one talk free by requesting an invitation to this zoom event. We're always delighted to welcome new members.
Many thanks to Michael Astrop for this report
Previous U3A reports on the HebWeb - click here