Fig. 2. Simulated potential structures for brain-behavior representational similarity matrices.

For each row a-d, the left panel depicts a simulated pairwise brain similarity matrix in which subjects are ordered along both rows i and columns j by their behavioral score (from low to high), and each cell {i, j} reflects the correlation between subjects i and j of the timeseries of a given brain region (pairwise inter-subject correlation). The right panel depicts a two-dimensional embedding of the corresponding distance matrix (i.e., 1 – similarity matrix) using t-SNE (t-Distributed Stochastic Neighbor Embedding), in which each dot represents a subject, and subjects are colored according to their behavioral score. Under the t-SNE solution, similar observations (in this case, subjects) appear nearby, while dissimilar observations appear further away.