Figure 1.

Avalanches in freely-behaving animals comprise families and recur above chance. (A) Avalanches represented as binary vectors in which colors indicate spike activity. Depicted are representative examples from four different samples of similar avalanche pairs separated by several minutes (interval of recurrence indicated on the right). (B) Similarity matrix for 200 representative avalanches from one sample, before and after clustering (left and right panels, respectively). Black lines indicate 10 families formed by similar avalanches. (C) Contrast function for one sample (colors represent different avalanche durations), with the maximum for one duration indicated by the dashed line. (D) Number of families of each size for one sample. Gray indicates all families detected (left Y axis); black indicates significant families (right Y axis). Note that the Y axes are scaled by a factor of 1000. (E) The recurrence over time of highly similar avalanches defines avalanche families. For the two representative families shown, the occurrence time is relative to the first observed avalanche.