Hot Spots

Christian Nold’s Bio Mapping uses collaborative filtering to figure out the best spots in town — and which locations to avoid. It’s an art project that doubles as a tourist guide.

Nold equipped hundreds of volunteers with GPS devices that also measure galvanic skin response (GSR), then sent them out to walk around several cities, including San Francisco, Rotterdam, Paris, and London. The GSRs, which gauge spikes in emotional arousal, allowed Nold to create maps of the cities’ stress centers and chill-out zones. It’s a striking new way of measuring our reactions to urban environments — and scientific proof that some days our emotions really are all over the map.