Man vs Mind

Everyday Psychology Explained

Daniel Richardson

• Publisher: Aurum
• Year: 2017
• ISBN:
  9781781317648
• Topic: Psicología
• Subtopic: Psicología social

Where do our thoughts come from? Do we all see the same blue? And how much is our eye really like a camera? The tool that sets humans apart from the rest of the animal kingdom, and the most crucial part of our very being – but what actually is it? From trying to decide whether or not we're robots, understanding why some people commit acts of violence, to figuring out the art of persuasion; this essential guide to the inner workings of our minds explores the questions we really want to know the answers to. Making the complex comprehensible, Daniel Richardson provides a new insight into how our minds work and the role they play in modern life. Whether it's pondering over why you're usually right about everything, or discovering colour; Man vs Mind shows that you don't need to be a psychologist to understand more about what's going on up there.

Mind vs mind

Where are our thoughts?

Our imagination, dreams, hopes, fears and loves, our understanding of distant galaxies, our knowledge of every contestant in Celebrity Big Brother. Are all these things really just the activity of a cluster of cells about the size of a disappointingly small pumpkin? How can thoughts be generated by something physical? Where exactly do they reside?

Try the following exercise, or ask the nearest person to you. (This is particularly good to do on an aeroplane. You’ll either have an interesting conversation or you’ll guarantee that they won’t speak to you again for the duration of the flight: either way, a win.) Point to where your thinking happens. If you are like most people, you’ll gesture vaguely towards your head. However, what evidence do you have for that belief? I’m asking for direct, personal experience. Unless you are a neuroscientist, you can’t say anything about brain-imaging experiments. What makes us think that thoughts reside in the head?

People’s answers tend to distil into a few categories. Maybe it’s just a cultural or linguistic habit. We speak about ‘keeping things under your hat’, ‘keeping your head’, and so on. Therefore, it’s just a belief that we pass on. Or perhaps it’s from the senses – our eyes and ears surround the head, so it seems as if that is the perceptual focal point of our experiences. It could be from biological design. Dense bone surrounds and protects your brain, suggesting that it’s pretty important to keep safe.

Throughout this first chapter, we will be sidling up to one idea in particular: what the neuroscientist Francis Crick called, in his book of the same title, ‘the astonishing hypothesis’. A version of this sentiment has been bandied about since the ancient Greeks, and the seventeenth-century philosopher Baruch Spinoza was a big fan. It’s worth reading in Crick’s prose:

‘You, your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules.’

We will discuss the evidence and implications of Crick’s astonishing hypothesis, tracing the struggle of man versus mind through the ages. We’ll look back through history for different answers to the question of where thought lies, from ancient Egyptians to modern neuroscientists. In addition, we’ll look at the reasons people had for locating the mind in particular parts of the body, and how we can reconcile ideas about the soul and conscious thought with emerging knowledge of the brain and nervous system.

From heart to head

In ancient Egypt, the heart was the centre of the self. They reasoned that it was right in the centre of the body, connected to everything by the veins. The heart develops first in the foetus. If you get an injury to the heart, even the tiniest nick from an arrow, you die. In contrast, you can get a blow to the head, and even have large chunks of your brain destroyed, yet still be a living, mostly functional person. The Egyptians thought the brain was unimportant – they called it ‘head marrow’ and guessed that it might be used to cool the blood. When a corpse was embalmed, they would yank out the brains using a bit of long bit of wire inserted up the nose and toss them aside as a treat for the cats.

While ancient Greeks such as the philosopher-scientist Aristotle concurred with the Egyptian view, a second-century philosopher-physician called Galen traced the nerves (rather than the blood vessels) and found that they all ended up at the brain. He argued that they were related to controlling the body, and demonstrated the point by severing the nerves of a lion, removing its ability to roar.

During the Renaissance, the drawings of the anatomist Andreas Vesalius and the polymath Leonardo da Vinci provided new insights into the structure of the brain, with intricate drawings of its ventricles, the gaps and holes that ran through it. The philosopher René Descartes imagined that these ventricles were like the pipes of a church organ; the soul was a type of wind flowing through and thoughts were the music it played.

However, in Descartes’ view the mind and the brain were fundamentally different things. He argued that there are objects in the world that are material, physical and spatial (that which scientists can measure and weigh) and there are things that are non-physical and non-material (the mind, thoughts and the soul). Descartes thought that, for each of us, our non-material soul interacts with our physical body via a tiny structure at the centre of the brain called the pineal gland. His basic notion of dualism – that mental things are different to physical things – remains influential today. It is endorsed by most religious viewpoints that have some notion of the soul or afterlife, or believe that human beings are more than their earthly bodies. It is also in direct conflict with Crick’s astonishing hypothesis: that we are simply the activity of cells.

Since Descartes, scientists have tried to locate mental function within the matter of the brain, rather than the realm of the soul. Anatomists in the 1600s, such as Thomas Willis and Nicolaus Steno, agreed that signals – the decision to move one’s hand, for example – were passing through the nerves. So what form did these signals take? Descartes had imagined the soul gusting through the ventricles of the brain, but the nerves throughout the body were not hollow. Perhaps nerves were like violin strings, transmitting information as vibration? They seemed too soft and pulpy, though. Perhaps thoughts were transmitted by a fluid? If so, scientists reasoned that if you put your hand in a beaker of water and decided to open and close your fist, the water level in the beaker should rise as you sent those fluid signals to your hand. To test it, they constructed tables carefully balanced like a seesaw. The scientists lay on the tables and thought really hard, expecting the table to tilt head-down, as the nerve-fluid rushed to the brain. These experiments, logical and ingenious as they were, failed to find the means by which nerves transmitted thought throughout the body. They were looking in the wrong place.

It's alive!

History has lost the exact circumstances under which we discovered the true means of a thought becoming an action, but it is said to involve some combination of a table, a blunt knife and a dead frog. In 1780, the physician Luigi Galvani was in the kitchen while some frogs were being prepared for dinner. The blunt knife needed to be sharpened and cleaned, and doing so on this occasion imparted a static electric charge to the blade. Galvani noticed that when the blade touched the leg of the frog, the dead animal twitched, as if its puppeteer had suddenly woken.

Many frogs later, Galvani had demonstrated in careful experiments that the nerves of frogs and other animals communicated by electrical discharge. He and other scientists graduated from rubbing static charges in metal to rigging up lightning conductors during storms to show the power of electricity over flesh.

It’s hard now to appreciate the significance of this moment. The dominant view then, as now, was that the mind was something mystical, a world apart from physical matter. Yet here, scientists had shown that the mysteries of willpower and the mind’s control of the body were somehow reducible to electrical phenomena and could be measured and controlled. In the following years, Galvani’s nephew, Giovanni Aldini, even reanimated the corpse of an executed criminal in London. It was early experiments such as these that the writer Mary Shelley had read about before she wrote her gothic horror novel Frankenstein, capturing the fear and philosophical shock of these discoveries.

Electricity was the essence of life, or its means of transmission, at least. It was the difference between a living and a dead body. But how does the brain generate and process these electrical impulses? At the end of the nineteenth century, scientists developed the means to stain brain cells so they could be viewed individually under a microscope. They discovered the neuron, and realised that the brain is made up of a dense network of these cells relaying electrical signals to each other.

Now we know there are approximately 80–100 billion neurons of various shapes and sizes in the brain. Each cell body has a long cable that sends out a signal, known as an axon, and a set of feathery, branching extensions called dendrites that receive signals from other axons. Where each axon and dendrite meets, there is a gap called a synapse, and each neuron has around 7,000 synapses. Chemicals called neurotransmitters flow across the synapse to transmit the electrical signals. The strength of the connection across the synapse can alter each time it is used, so that each time the axon fires a signal, the synapse has a slightly different response. This is learning. Brain activity is 80 billion interconnected processing units, each relaying electrical activity to 7,000 of its neighbours, all changing their responses with each wave of activity, learning and adapting to input.

Walking cats and dreaming rats

We can measure the brain's electrical activity with the same device that an electrician would use to test a circuit. Small probes can be inserted into brain tissue and the electrical signal of cells can be measured. In the 1950s neurophysiologists David Hubel and Torsten Wiesel did this first with cats who were awake. They passed a black line on a white card in front of a cat’s eyes and measured activity from a particular cell that fired only if the line was horizontal and in a particular location.

More recently, neuroscientist John O’Keefe and his colleagues inserted clusters of probes, each finer than a human hair, into a brain structure known as the hippocampus – in this instance, using rats. The animals wore the device while running through a maze. After they felt at home in the maze, the researchers noticed that when a rat was in a particular location, the same cell in the hippocampus would fire; at another location, ...