On May 21st, the symposium ‘Dialogues on the role of top-down factors in sensory processing’ took place. I organized this event together with Floris de Lange and Peter Kok. We had an extremely nice line-up of speakers: Karl Friston, Chris Summerfield, Pieter Roelfsema, Tobias Donner, Sid Kouider and Moshe Bar. 200 visitors from all over Europe came to Nijmegen to attend the discussion. We had three sessions, one of which was moderated by me. We discussed the question: does the human brain implement predictive coding? Friston and Roelfsema had actually opposing views on this, which resulted in an entertaining and very interesting debate.