Research Article

Structural Brain Imaging Phenotypes of Mild Cognitive Impairment (MCI) and Alzheimer’s Disease (AD) Found by Hierarchical Clustering

Figure 12

The metric based on which the clusters are merged as a function of the number of clusters. The metric appears rather flat until the number of clusters has decreased to about 200. Within the range of about 50-200 clusters, the internal coherency of the clusters gradually starts degenerating because of “forced” mergers with outliers. Computation proceeds in the direction of decreasing the number of clusters as indicated.