Different but related: this morning, my DS could not be moved to dress and prepare for school because he was entirely absorbed in packing up a new board game he and his sister designed last night that is a Risk-inspired Vietnam War strategy game. He took it to school with a bunch of army men. It took him twice as long to get dressed as usual (and usual is already ridiculously long) and nothing I did moved him out of his head space.
He's a super creative and also perseverative kid. He doesn't pace and mutter but he does talk to himself as he engineers his activities and ability to SHIFT appears to be really impaired.
I'm choosing to look at this as a little bit of both in terms of creative v. pathology. For my DS it is EF. There are up sides to the hyper focus, also, but it does interfere with functioning.
