Thanks Debbie, I had already figured it out (but only after a brief period of perseveration on the sentence!). Given that the people in my life who perseverate are very dear to me, I think that I will continue to use the word "hyperfocus" because I think, like Webb says, it sounds "less medical" and at least to my ear more respectful! "Honey, you're perseverating again," just doesn't sound like the begining of a conversation that will end well!

It was DH's inability to switch focus easily that resulted in our seeking a diagnosis. When DS was about 2, DH found he had to switch focus approximately a million times per day and it left him totally frazzled ("frazzled" being the technical term I believe).