A brain–computer interface reads the electrical signals of neurons and turns them into actions: cursor movement, letters on the screen, commands for devices. For people with paralysis it means getting back a voice and independence: writing a message, opening email, controlling a computer by thought. Today this is medicine and clinical trials; in March 2026, China approved the first implantable interface for people with spinal cord injuries.
How it works
Every movement starts in the brain. When a person is about to move a hand, neurons in the motor cortex send short electrical impulses — spikes. Even if the signal does not reach the muscles because of a spinal cord injury, the pattern of activity in the cortex remains: the brain keeps giving commands. The interface connects right here — at the point where the intention already exists but the path to the hand is cut.
Thin electrodes — flexible threads or a tiny grid — are placed next to neurons, and each one hears the nearest cells, like a microphone in a noisy hall. The signals are amplified, digitized and sent wirelessly to a computer. There a decoder runs — a machine learning model. The person imagines movements, and the model learns which pattern means what: “up”, “left”, “click”. After this calibration the cursor goes where the person wants.
Newer systems decode not only movements but also attempted speech: the model recognizes the sounds and words a person is trying to say and assembles them into text. There are options that do not require opening the skull — a sensor inside a blood vessel or a cap with EEG electrodes — but the signal through bone is weaker and coarser. The main questions today are how long electrodes last in the body, decoder accuracy and the safety of the surgery.
Where it already works
- People with paralysis: typing text and controlling a computer by thought.
- China: in March 2026, the first implantable interface for spinal cord injury was approved.
- Neuralink’s clinical trials — 21 participants as of January 2026.
- Research on speech interfaces: an attempt to say a word becomes text on the screen.
What to consider
- This is medicine: access is only through clinical trials and regulator-approved programs.
- An implant requires brain surgery — doctors make the decision together with the patient.
- Store-bought EEG headsets read the brain coarsely — that is not the same as an implant.
- Neural data is the most personal data there is: ask where it is stored and who sees it.