By Kevin Randall | The New York Times | November 3, 2015

In the lobby of a Mexico City office building, people scurrying to and fro gazed briefly at the digital billboard backing a candidate for Congress in June.

They probably did not know that the sign was reading them, too.

Inside the ad, a camera captured their facial expressions and fed them through an algorithm, reading emotional reactions like happiness, surprise, anger, disgust, fear and sadness.

With all the unwitting feedback, the campaign could then tweak the message — the images, sounds or words — to come up with a version that voters might like better.

All over the world, political campaigns are seeking voter data and insights that will propel them to victory. Now, in an increasing number of places, that includes the contentious field known as neuromarketing — or in this case, neuropolitics. Continue reading »