Apparently, he's been doing this for 3 years, and his latest project is San Francisco. He's also made emotional maps of parts of Siena, Italy, Munich, and Germany. Here's his website.How does he do it?
"First, he outfits volunteers with global positioning system devices and the sensors used in lie detector tests. Then, he sends his subjects out to wander their neighborhoods. When they return, Nold asks them to recount what they saw and felt when the polygraph recorded a quickened heartbeat or an elevated blood pressure."