Controlling a computer with just your thoughts seems to be something straight out of a science fiction movie, but that’s exactly what scientific experiments are now doing. This week Elon Musk, founder of the startup Neuralink which implanted a brain chip, called Telepathy, into a human being last month, said that the patient’s progress has been good, and the patient is now able to move a mouse on a screen by just thinking. Exciting? Yes. A little scary too? Perhaps. The tech, at least for now, is aimed at treating paralysis and complex neurological conditions.

Putting electrodes into the brain is not new – scientists have been experimenting with this for years now, but refining and potentially commercialising this tech takes a lot of doing.

The brain is a complex organ that works by sending electrical impulses from one neuron to another every time we think, and we have 86 billion neurons. The brain-computer interface technology attempts to capture some of this activity through a chip that acts as a bridge between the brain and a digital device.

So what does brain-computer interface technology involve, and how does it work? How many of our brain signals can be read? What is its potential in medical applications to treat health conditions? And importantly, what are the ethical issues involved here?