Department of Psychology, University of Fribourg, Rue de Faucigny 2, 1700 Fribourg, Switzerland. Contents lists available at SciVerse ScienceDirect Applied Ergonomics journal homepage: www.elsevier.com/locate/apergo 0003-6870/$ e see front matter
2012 Elsevier Ltd and The Ergonomics Society. All rights reserved. http://dx.doi.org/10.1016/j.apergo.2012.09.004