From Wired:

The setup is simple: An off-the-shelf EEG brainwave sensor made by NeuroSky is built into a standard helmet. To make the map, eight riders spent September and October riding most of Manhattan (favoring north-south thoroughfares over east-west cross streets). Every second, the EEG sensor sends, via Bluetooth, data on the rider’s level of focus. Attention level rises when the user focuses on one thing (say, a car about to swerve into the bike lane), and decreases when they’re less focused. In other words, it provides an idea of where you’re totally stressed and when you’re chill. A riders’ level of attention was ranked from 0 to 100, then correlated onto a color scale, from green to yellow to red.

Bike Brain

… there are some broad takeaways:

Biking through congested midtown and lower Manhattan requires more focus. In calmer areas of the borough where bike lanes are common, you can relax. The most surprising find is that having a bike lane doesn’t necessarily make riding calmer: It can provide security from cars, but also be crowded by other cyclists and errant pedestrians (who, in New York, are as much a threat to cyclists as cars are). “A bike facility in itself doesn’t call for a sweet spot,” Sta. Ines says.

Full article and interactive map here.