1 Macro Connections, The MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139;
2 Department of Physics, Northeastern University, Boston, MA 02115; Aix-Marseille Université, CNRS, Centre de Physique Théorique, UMR 7332, 13288 Marseille, France; Université de Toulon, CNRS, Centre de Physique Théorique, UMR 7332, 83957 La Garde, France; and.
3 Department of Physics, Northeastern University, Boston, MA 02115;
4 Department of Psychology, Harvard University, Cambridge, MA 02138.
5 Macro Connections, The MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139; hidalgo@mit.edu.