1. Neurobiology of Social Communication, Department of Otolaryngology - Head and Neck Surgery, Medical Center, University of Tübingen, 72076 Tübingen, Germany.
2. Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, 72076 Tübingen, Germany.
3. Laboratory of Neural Systems, The Rockefeller University, New York, NY 10065, USA.
4. Cognitive Ethology Laboratory, German Primate Center, 37077 Göttingen, Germany.