The map here is from a project by Christian Nold, a London-based artist, using technology to measure levels of stimulation. Here's a project summary.
Bio Mapping is a community mapping project in which over the last four years with more than 1500 people have taken part in. In the context of regular, local workshops and consultations, participants are wired up with an innovative device which records the wearer's Galvanic Skin Response (GSR), which is a simple indicator of the emotional arousal in conjunction with their geographical location. People re-explore their local area by walking the neighbourhood with the device and on their return a map is created which visualises points of high and low arousal. By interpreting and annotating this data, communal emotion maps are constructed that are packed full of personal observations which show the areas that people feel strongly about and truly visualise the social space of a community.