[1] Knappsch Krakenhaus Recklinghausen, Klin Neurophysiol, D-45657 Recklinghausen, Germany
[2] Univ Klinikum Duisburg Essen, Neurol Klin, Duisburg, Germany
[3] Ruhr Univ Bochum, Inst Kognit Neurowissensch, Bochum, Germany
[4] Ruhr Univ Bochum, Abt Neuroanat & Mol Hirnforsch, Bochum, Germany