Mentorship-derived clusters.

<p>Clusters were derived by spectral factorization of the sparse matrix of mentor relationships between all researchers connected in the main Neurotree graph. Each box describes a cluster, numbered according to the average generation of researchers in the cluster. Clusters are plotted in roughly chronological order from top to bottom. Each cluster is labeled with the names of the two researchers with the smallest mean distance to other researchers in the cluster and by the two most common research areas in the cluster. Lines connecting clusters indicate the relative strength of connections between them (dotted: 1–5, solid: 6–20, bold: 21+).