It’s possible to tell what a person is thinking. Our brains give off different signals when we think of different things. The brain waves for thinking of moving our left foot and our right hand, or thinking a happy thought versus thinking a sad thought are different.
If a person wears a special cap with sensors that pick up their brain waves, then a computer can tell the difference.
It is used to give totally paralysed people a way to speak, or control a wheelchair.
Superhero powers: reading minds