How to read minds
by Dr Damian Cruse
Where is my mind? Some brain facts
All of your thoughts and experiences are Your brain contains 80-billion neurons
the result of your brain cells (neurons) that communicate with one another
sending signals to each other in a through small electrical signals.
process we call neural firing.
When you’re a baby, your neurons have
In fact, your thoughts and experiences, about 50% more connections with one
and all of who you are, is the firing of another than when you’re an adult.
your neurons. During adolescence, you lose those
extra connections – a process called
Just like a video on your phone is synaptic pruning – as your brain
actually just a set of tiny voltages across becomes specialised for the world in
transistors on the phone’s microchips, which you live.
your thoughts and experiences are
actually just tiny electrical signals across Brain injury is the leading cause of death
neurons in your brain. and disability in the world. You should
look after your brain.
Some ways to measure brain activity
Because your neurons communicate with each other through electrical
signals, we can detect the electrical activity of your neurons by measuring
the tiny voltages they create on the surface of your head – a method called
electroencephalography (EEG).
When neurons fire a lot, they use up more oxygen, just like you might
breathe faster after exercising. This means that we can measure neurons
firing by measuring which parts of the brain use oxygen most – a method
called functional magnetic resonance imaging (fMRI) that requires a
doughnut-shaped magnet about 500-times stronger than a fridge magnet.
Oxygenated blood is more red than deoxygenated blood. If we fire
(harmless) lasers into your skull, we can measure the ‘colour’ of the brain
underneath, and use that colour to work out which parts of the brain are
using oxygen most, and are therefore most active. This is called functional
near-infrared spectroscopy (fNIRS).
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A significant problem
Every day in the United Kingdom, twenty people are taken to hospital because they
appear to be unconscious after a brain injury. Some of these people develop a
Prolonged Disorder of Consciousness in which they open their eyes again but
show little or no evidence that they are conscious of themselves or their
environments.
To make the best medical decisions for these patients, we need to know whether they
are conscious or not. Because they can’t physically show us that they are conscious
by, for example, giving us a thumbs-up when we ask them to, we need to be able to
read their minds instead.
Helping people
Reading minds with brain injuries
Once we’ve chosen how we’re going to If a person in hospital can’t physically
measure brain activity, we can start to give us a thumbs-up to show that
read minds. Using knowledge from they’re conscious, but they can
Psychology and Neuroscience, we can imagine giving us a thumbs-up instead,
read out how different thoughts are we could read that thought using our
represented in the brain. measures of brain activity and know
that they’re conscious.
For example, we can detect whether
someone is imagining moving their As technology becomes more
hand or their foot, just by looking at advanced, people who are paralysed
their brain activity. Brain-computer by their injuries are beginning to have
interfaces can then translate that access to devices that can translate
thought into an action, such as their thoughts for communication.
controlling a character in a video game.
Things to think about
• If your mind is in your brain, could a machine ever have a mind and be conscious?
• How could we ever know if a machine is conscious?
• Are animals conscious in the same way as humans?
• What would this mean for the ethics of animal welfare?
• How are you making sure to keep your brain and mind safe and healthy?
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