In a recent groundbreaking operation, a man paralysed from the neck down is now, after eight years, able to eat and drink without assistance – all thanks to the power of thought.
The story has captured everyone’s imagination because it seems miraculous that paralysis can be reversed simply by our thoughts. But neuroscientists have always known the information is there, it’s just a question of how you read it out.
In this instance scientists did not tap into the spinal cord. Instead, they used an implant in the patient’s head to read out his intentions from the motor cortex. In this part of the brain, which plans and controls movements, the various parts of the body are laid out like a map. This means that the intended actions can be read out by a sensor, like a message on a mobile. The scientists can then ‘spy’ on the signals and work out the neural trace of his movements. They are then relayed directly to the muscles, allowing the patient to move his arm.
It turns out that in neuroscience as in life, it’s often worth cutting out the middle man and tracing a story directly to its source.
Dr Daniel Glaser is director of Science Gallery at King’s College London
