1 Department of Medical, Clinical, and Experimental Psychology, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands Pain Management and Research Center, University Hospital Maastricht, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands Department of Behavioural, Social and Legal Sciences - Psychology, Örebrö University, Örebrö, Sweden.