Figure 18. Extent of Global Autism Research and International Collaborations in 2010. 

World map. This world map is a heat map indicating the amount of autism articles published per country in the year 2010 as well as the number of times countries collaborated on the same publication.  The map indicates that the United States published the most articles, totaling 1,040.  The next highest group, which published between 101 and 300 articles, is populated by Canada and the United Kingdom. Connecting lines between countries represent author collaboration, where thicker and darker lines indicate a greater degree of shared publications between country pairs.  The most collaborations, between 31 and 40, occurred between the United States and Canada as well as between the United States and the United Kingdom.  The second highest degree of collaboration, from 21 to 30 publications, was observed between the United States and the Netherlands and between the United States and Italy.  For the full list of countries that published ASD research articles and their publication counts, refer to Table 2 and Appendix seven.  For a full list of country collaboration pairs and number of collaborations on articles published in 2010, refer to Appendix six.