A mind-reading device can answer questions in your head. It works by picking up signals sent from your brain when you think about saying something

Arnav Kapur models the AlterEgo device he co-created Lorrie LeJeune, MIT

SILENTLY think of a question and I will answer it. That might sound like a magic trick, but it is the promise of AlterEgo, a headset that lets you speak to a computer without ever uttering a sound. It’s not quite a mind reader, but it is close.

The device brings us a step closer to a world where we can interact seamlessly with machines using only our thoughts. AlterEgo’s creators believe that rather than embarrassingly saying things like “OK Google” or “Hey Siri” and then dictating an email …