[1] UCL, Inst Cognit Neurosci, London WC1N 3AR, England
[2] UCL, Dept Psychol, London WC1N 3AR, England
[3] UCL, Dept Human Commun Sci, London WC1N 3AR, England
[4] Univ London Goldsmiths Coll, Dept Psychol, London SE14 6NW, England
[5] Birkbeck Coll, Brain & Behav Lab, London, England
[6] Univ Essex, Dept Psychol, Colchester CO4 3SQ, Essex, England
[7] Univ Jena, Inst Psychol, D-6900 Jena, Germany
[8] UCL, Inst Neurol, Dementia Res Ctr, London WC1E 6BT, England