About the Authors

Karl-Heinz Konopka

k.h.konopka@umcg.nl

Affiliation Department of Anesthesiology, Pain Management Unit, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Marten Harbers

Affiliation Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Andrea Houghton

Affiliation Merck & Co., Inc., West Point, Pennsylvania, United States of America

Rudie Kortekaas

Affiliation Department of Neuroscience, Neuroimaging Center, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Andre van Vliet

Affiliation PRA International, Zuidlaren, The Netherlands

Wia Timmerman

Affiliation PRA International, Zuidlaren, The Netherlands

Johan A. den Boer

Affiliation Department of Psychiatry, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Michel M. R. F. Struys

Affiliation Department of Anesthesiology, Pain Management Unit, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Marten van Wijhe

Affiliation Department of Anesthesiology, Pain Management Unit, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Competing Interests

AV and WT are employed by PRA International, Netherlands and AH is employed by Merck & Co.,Inc, USA. KHK, MH, RK, JB, MS and MW have disclosed no competing interests. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: KHK MH WT JB MW AV AH. Performed the experiments: KHK MH. Analyzed the data: KHK MH. Wrote the paper: KHK MH WT JB MW AV AH RK MS. Obtained permission: KHK MH WT JB MW AV AH RK MS.