If an issue has been fully explored and discussed to a point of resolution it is not uncommon for something to trigger the re-investigation of the matter. This can happen at any time during a conversation. This is particularly true with those who have had traumatic brain injuries.
Those with Asperger's syndrome also display a form of perseveration in that they focus on one or a number of narrow interests. A person with Asperger's might go to a department store repeatedly to look at air conditioners.
Several researchers have tried to connect perseveration with a lack of inhibition; however, this connection could not be found, or was small.