[1] Univ Sheffield, Dept Psychol, Sheffield S10 2UR, S Yorkshire, England
[2] Royal Hallamshire Hosp, Neuropsychol Unit, Sheffield S10 2JF, S Yorkshire, England
[3] Univ York, Dept Psychol, York YO1 5DD, N Yorkshire, England
[4] MRC, Appl Psychol Unit, Cambridge CB2 2EF, England
[5] Univ Sheffield, Royal Hallamshire Hosp, Dept Neurol, Sheffield S10 2JF, S Yorkshire, England
[6] Univ Cambridge, Addenbrookes Hosp, Neurol Unit, Cambridge CB2 2QQ, England
[7] Univ Paisley, Dept Appl Social Studies, Paisley PA1 2BE, Renfrew, Scotland
[8] Univ Liverpool, Magnet Resonance Res & Image Anal Res Ctr, Liverpool L69 3BX, Merseyside, England
[9] So Gen Hosp, Inst Neurol Sci, Glasgow G51 4TF, Lanark, Scotland