A 36-year-old German man in a completely locked-in state was outfitted with a novel brain-computer interface (BCI) system that relies on auditory feedback. The man learned to alter his brain activity in response to that auditory feedback to compose simple messages. He used this ability to ask for a beer, for his caretakers to play his favourite rock band, and to communicate with his young son, according to a recent paper published in Nature Communications.
BCIs interact with brain cells, recording the electrical activity of neurons and translating those signals into action. Such systems generally involve electrode sensors to record neuronal activity, a chipset to transmit the signals, and computer algorithms to translate the signals. BCIs can be external, similar to medical EEGs in that the electrodes are placed onto the scalp or forehead with a wearable cap, or they can be implanted directly into the brain. The former method is less invasive but can be less accurate because more noise interferes with the signals; the latter requires brain surgery, which can be risky. But for many paralysed or locked-in patients, it's an acceptable risk.
See BCI lets completely “locked-in” man communicate with his son, ask for a beer
System trains the user to alter their brain activity in response to auditory feedback.