CAN EPILEPTIC SEIZURES BE PREDICTED? At the Clinic of Epileptology at the University of Bonn (located on Sigmund Freud Strasse), one of the largest centers for epilepsy surgery in the world, doctors must locate the source of seizures as accurately as possible so as to minimize post-operative loss of brain activity once the offending tissue has been removed. To do this Klaus Lehnertz (klaus@jersey.meb.uni-bonn.de) and Christian Elger scan suspected trouble areas in the brain; they monitor EEG patterns over time and look not just at the rapid, violent neuronal firings during an epileptic attack but at the electrical landscape before and after the brainstorm. In particular, they look for suspicious changes in the "correlation dimension," a number which typifies the local complexity of neural activity. In some patients they see a decrease in the correlation dimension which, they believe, corresponds to the sort of increasing synchronization in the pathological firing of neurons that (above a critical level) leads to a seizure. The Bonn researchers argue that this identification and study of the pre-seizure state in the brain should result in a better understanding of how seizures come about and might suggest new ways (chemical, electrical, or psychological) of preventing seizures. (Physical Review Letters, 1 June 1998.)