Network similarity.

<p><i>Upper panel</i>: Comparison between the spatial profile of the ‘pain matrix’ and each of the other seven networks. Voxels are represented on the x-axis, normalized values of the ALE maps on the y-axis. <i>Middle right panel</i>: 1D Spatial similarity (expressed as spatial correlation) between the pain matrix and each of the other seven networks. The task-related networks are placed along the vertical axis on the basis of the spatial similarity with the pain matrix. The more a network is shifted towards the upper part of the graph the more its spatial pattern is similar to the spatial pattern of the pain network. <i>Middle left panel</i>: Circular plot showing the spatial similarity between networks. Similar networks are connected by a line. Network names are shown along the outside of the circles. The lines are intended to represent similarity (Spatial correlation) between networks. The width of the bands is proportional to the spatial similarity (expressed in percentage reported in the outer circle)explained by each network. Colors are chosen for representational purposes and have no statistical meanings, similarities with the pain network are coded in red. Circular plots were generated using Circos (<a href="http://mkweb.bcgsc.ca/circos/" target="_blank">http://mkweb.bcgsc.ca/circos/</a>). <i>Lower right panel</i>: Distance matrix and hierarchical clustering of the eight networks. Networks with a low distance (distance = 1-spatial similarity) are placed close to each other. When a group of networks shows a high similarity it is grouped into a cluster sharing a similar spatial pattern. <i>Lower left panel</i>: Multidimensional scaling of the spatial profiles of the eight networks. Multidimensional scaling is a technique which finds a low-dimensional projection of points, where it tries to fit the given distances between points as well as possible. Points that are placed closely to each other have a similar spatial pattern. Points placed distantly from each other are characterized by a very different spatial pattern.