[1] Kings Coll London, Inst Psychiat, Dept Psychol, London WC2R 2LS, England
[2] Kings Coll London, Inst Psychiat, Sect Cognit Psychiat, London WC2R 2LS, England
[3] E Kent NHS Fdn Trust, Ashford, Kent, England
[4] NHS Fdn Trust, Kings Coll Hosp, Dept Neurol, London, England