Was just thinking more about ADHD cats, and then the issue of focus.
During a recent California trip, I discussed "dynamic focus" models with a number of people. The model is rather like the center-surround organization of sensory receptive fields. The difference is that the emphasis here is upon behavioral production.
As activity in systems increases one often gets the sense that the system tightens its focus, blocking out irrelevant messages. We focus our attention, and avoid interruptions, etc. For ADHD and a number of other disorders, this dynamic focusing seems to go wrong. Actions can be scattered at one extreme, or perseverantly stereotyped at another. Attention can get switched when it should not, and stuck when it should switch. My bet is that there are still unknown rules about this. ADHD is perhaps as good a model to think about as any.
I'd love to hear (read) reactions.