Where does your interest in the issue of predictive coding and processing (PCP)-which has been noticeable for at least seven years-come from? It started around 1999 when I shared an office with Ian Gold (now McGill) at the Australian National University, when I was doing my PhD. Ian was doing postdoc work in philosophy of psychiatry and he introduced me to Chris Frith's theory of delusion formation, which builds on efference copy mismatches. We went on to write a paper about delusions,

more »

... the idea that some delusions arise as rational responses to unusual experiences. Though this story is changing somewhat these days, the efference copy notion is important because it solves a difficult processing problem through the use of predictions and comparisons. This is central to PCP and made me interested in it immediately. Later, I moved to Aarhus in Denmark and there I quickly began collaborating with Andreas Roepstorff, the anthropologist and cognitive scientist, who was at that time beginning to set up an interdisciplinary network of researchers interested in culture, communication and cognition (now morphed into the fabulous Interacting Minds Centre). Andreas had done anthropological fieldwork in Chris Frith's lab in London and invited Chris and Uta Frith to come and stay in Aarhus. Their visits kindled my interest in getting to understand more about general brain function. A key point was when the mathematician and semiotician Svend Østergaard did a journal club presentation on Karl Friston's paper "Beyond phrenology", one of the first papers pushing the PCP line. Andreas and I quickly saw the great potential of this way of thinking about brain function. We conducted our very first functional MRI study inspired by PCP (a failed venture, we tried to replicate the classic Perky effect), and around 2005 organized a workshop on predictive