[1] UCL Inst Child Hlth, Neurosci Unit, London, England
[2] UCL Inst Child Hlth, Dev Cognit Neurosci Unit, London, England
[3] Natl Soc Epilepsy, London, England
[4] UCL Inst Neurol, Dept Clin & Expt Epilepsy, London, England
[5] UCL Inst Child Hlth, Radiol & Phys Unit, London, England
[6] Great Ormond St Hosp Sick Children, Dept Clin Neurophysiol, London WC1N 3JH, England
[7] UCL Inst Neurol, Dept Clin Neurophysiol, London, England