The arms race in Silicon Valley is on for artificial intelligence.
Facebook is working on a virtual personal assistant that can read people's faces and decide whether or not to let them in your home.
Google is investing in the technology to power self-driving cars, identify people on its photo service and build a better messaging app.
Now Apple is adding to its artificial intelligence arsenal. The iPhone maker purchased Emotient, a San Diego maker of facial expression recognition software that can detect emotions to assist advertisers, retailers, doctors and many other professions.
Apple confirmed the purchase this month, but did not give details of the deal....