The brain does not choose the shortest way when we have to choose a path. To shed light on this behavior is a study by the Institute of Informatics and Telematics of the CNR of Pisa, carried out in collaboration with the MIT of Boston and the Polytechnic of Turin, which demonstrates how pedestrians choose the paths without calculating the shortest one to reach the destination. To carry out the research, the study used the data of the walking mobility of 14 thousand people. The work – published in Nature Computational Science
– could be strategic for better design the cities of the future thanks to more effective and safer and also more pleasant movements of citizens.
In the study, the researchers explain that the shortest distance between two points is a straight line, but when we walk in a city, the direct path to the destination may not be possible. So, how do we decide which path to take? The new study – carried out by a team of the Institute of Informatics and Telematics of the National Research Council (CnrIit) of Pisa in collaboration with the Massachusetts Institute of Technology (MIT) and with the Polytechnic of Turin – demonstrates that our brain is not optimized to calculate the so-called ‘shortest path’ when traveling is pedestrian. The research team analyzed a data set of over 550,000 walking trips of over 14,000 people in Boston and San Francisco and found that pedestrians tend to choose paths, called ‘directional paths’, which seem to point directly to their destination even if they may eventually turn out to be longer than the ‘shortest path’.
Paolo Santi, research director of Cnr-Iit, underlines that “this strategy, known as vector navigation, has been observed in previous studies on animals, from insects to primates. Vector navigation is used because it requires fewer brain resources than having to calculate the so-called shortest path. This brain energy saving could be the result of evolution, in order to leave the brain more resources to perform other activities for survival. “In short, the mind distributes the energies between the different computing activities. “There seems to be a mechanism that allocates the brain’s computational resources for other uses: thirty thousand years ago, for example, to escape from a predator and today to avoid a dangerous area due to excessive traffic“says Carlo Ratti, professor of urban technologies at MIT’s urban studies and planning department and director of the Senseable City Lab.
Alessandro Rizzo, professor of automation and robotics at the electronics and telecommunications department of the Polytechnic of Turin, explains that “vector navigation does not produce the shortest path, but a path sufficiently close to the shortest one, easier to calculate and therefore with less brain energy expenditure. ”The study results could then be used for urban planning.
“The potential contained in the travel data of individuals is enormous. Having identified uniform behavioral characteristics in cities with such different characteristics – Rizzo points out – gives us hope in the possibility of using these data to better design the cities of the future, making the movements of citizens more effective, safer and, why not, pleasant “.
They contributed to the study Christian Bongiorno (first signatory), associate professor at the Université Paris-Saclay, Alessandro Rizzo, professor of automation and robotics at the Department of electronics and telecommunications of the Polytechnic of Turin, and Joshua Tenenbaum, professor of computational and cognitive sciences at the Center for the study of the brain, mind, and machines of the MIT Department of Brain and Cognitive Science.