T hese definitions are not in DSM-IV but perhaps they will make it into DSM-V.
Hyperdigression: An uncontrollable proclivity to shift attention to objects or subjects that are either tangentially related or completed unrelated to the current object or subject of attention. This action often induces another round of hyperdigression ad infinitum.
Jingling: the tendency to associate one’s activities with television or radio commercial jingles and to sing all or part of that jingle. In the case of television commercials, the person may act out all or part of it during the jingling episode.
EXAMPLE: A person suffering from hyperdigression will be engaged in a conversation about some food item, say, a banana. Thinking about that banana triggers spontaneous jingling. The hyperdigressor stands up, places hands on hips, sways like Carmen Miranda and starts to sing, in a slightly Hispanic accent, “I’m a Chiquita banana and I’ve come to say….” This, in turn, triggers the memory of an old television show which, in turn, triggers the memory of a long gone, but beloved, toy which, in turn triggers a toy-related episode of jingling.