[1] Univ Cambridge, Dept Psychiat, Cambridge, England
[2] Univ Cambridge, Fac Educ, Cambridge, England
[3] Univ Bath, Dept Psychol, Bath BA2 7AY, Avon, England
[4] Univ Exeter, Dept Psychol, Exeter EX4 4RJ, Devon, England
[5] Univ Bern, Dept Psychol, Bern, Switzerland
[6] Univ Dundee, Sch Nursing & Hlth Sci, Dundee, Scotland
[7] MRC, Cognit & Brain Sci Unit, Cambridge, England