[1] Univ Warwick, Warwick Med Sch, Clin Trials Unit, Coventry, W Midlands, England
[2] Univ Warwick, Warwick Med Sch, Div Hlth Sci, Coventry, W Midlands, England
[3] Univ Southampton, Southampton, Hants, England
[4] Univ Warwick, Dept Psychol, Coventry, W Midlands, England
[5] Univ Hosp Coventry & Warwickshire NHS Trust, Dept Neurol, Coventry, W Midlands, England
[6] Dystonia Soc, West Midlands Grp, London, W Midlands, England
[7] Univ Warwick, Dept Comp Sci, Coventry, W Midlands, England