The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk|The Wellcome Trust Centre for Neuroimaging, University College London, Queen Square, London, United Kingdom. k.friston@fil.ion.ucl.ac.uk