How do brains detect novelty?
Festschrifts are among the wonderful inventions of enlightened minds. They serve many purposes. The main purpose, of course, is to honour the honouree and make him happy. Sometimes this purpose does not work because not all great scholars and scientists for whom Festschrifts are written know how to be happy. In the present case, however, the success of this part of the venture is assured because our honouree, Lars-Göran Nilsson, not only believes in happiness but also practises it wherever and whenever possible. In that sense alone, this Festschrift in his honour is especially appropriate. Festschrifts also make Festschrift organizers happy, not only because they can thereby publicly express their respect and admiration for the honouree but also because it makes for a handsome addition to their own curricula vitae. And Festschrifts make the invited contributors happy because it sometimes aﬀords them a chance to publish something that they might not be allowed to publish under less friendly circumstances. As a contributor I am grateful to Lars-Göran Nilsson for laying the groundwork for such an opening, and to Lars Bäckman and Lars Nyberg for eﬀecting it, thereby making it possible to tell the story that appears here.