Brain-reading device is best yet at decoding ‘internal speech’

A brain-computer interface device is the first to decode words entirely from neuronal recordings, without the aid of spoken or mimed speech. The system used arrays of tiny electrodes implanted in the brains of two people with spinal-cord injuries. It decoded one participant’s imagined speech with 79% accuracy and the other’s with 23% accuracy. Some neurons were active only during internal speech and not when the person spoke aloud, suggesting the brain processes imagined speech differently. Clinical applications are still a long way off.