It is unequivocally proven in my experience: Nothing draws a cat's attention like a model train/monorail rolling around a layout.
Aurora has been largely disinterested in my construction of this year's under-the-tree layout, poking in lazily a few times. But once I got the monorail running, she has turned up every time I turn it on.
This has been the same reaction of any cat I've lived with (four now). Nap-time, lunch-time, be in the other room as quickly as possible for no apparent reason-time, it makes no difference. I start running the tracked vehicles and they almost always come.
Aurora didn't start swatting it off the rail yet (a favorite pass time of the late Avalon when she was younger), but she hasn't had much opportunity. Right now I only run it a lap or two to check the fit of new construction.
This time she came running as I turned it on to test the freshly-finished rear wall of the Dinos & Friends layout. Note how she dwarfs the Lego T-Rex at the wall.
Other construction Tuesday night: A gate for a tunnel (from a Thomas the Tank Engine Duplo kit) I used to make an underground river connecting the separate lakes on each side, and a revised, open-air monorail passenger car.