Kühn, K
Cott, C
Bohler, S
Aigal, S
Zheng, S
Villringer, S
Imberty, A
Claudinon, J
Römer, W
Article History
Received: 19 June 2015
Revised: 3 August 2015
Accepted: 7 August 2015
First Online: 21 September 2015
Competing interests
: The authors declare no conflict of interest.