  It is shown that, contrary to the claims in a recent letter by Haldeman and
Beggs (PRL, 94, 058101, 2005), the branching ratio in epileptic cortical
cultures is smaller than one. In addition, and also in contrast to claims made
in that paper, the number of metastable states is not significantly different
between cortical cultures in the critical state and cultures made epileptic
using picrotoxin.

Neurons and Cognition;Disordered Systems and Neural Networks