What's the Latest Development?

By scanning the brain, scientists are increasingly able to tell what a person is thinking about. Three recent studies demonstrate the frontiers of real-life mind-reading. The first looked at dreaming and whether certain parts of the brain operate the same whether a person is awake or dreaming. When an individual clenched his fist in a dream, his brain registered the action as though he were awake. In principle, then, we could know what someone is dreaming about by "reading" the dream as it occurs.

What's the Big Idea?

Two other studies conducted at Berkeley and Princeton looked at awake minds. The first, using sheer computer power, was able to reconstruct data from the brain's visual cortex to give a pictorial representation of what the person was watching—film trailers, in the experiment. The second took large swaths of data on what happened to a person's brain when they imagined a given object. By compiling the data, scientists were able to guess with some accuracy what a person was pondering.