2 The Bartlett School of Environment, Energy and Resources, Faculty of the Built Environment, University College London, London, UK.
3 Epilepsy Society, Chalfont St Peter, UK.
4 Epilepsy Society, Chalfont St Peter, UK; UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK. Electronic address: s.sisodiya@ucl.ac.uk.