Apple Inc. has purchased Emotient Inc., a startup that uses artificial-intelligence technology to read people’s emotions by analyzing facial expressions.

Fascinating technology. There are a number of uses for it, including advertising, but I don’t think that’s what Apple will use it for.

Doctors also have tested it to interpret signs of pain among patients unable to express themselves, and a retailer used it to monitor shoppers’ facial expressions in store aisles, the company had said.

Both of those options seem viable to me, especially the medical angle, given Apple’s foray into helping the medical profession recently.