The closest thing to "automatic drawing" I've experienced occurred when I was awarded a one-person show at a downtown Los Angeles gallery.
At first, I freaked! I had a few paintings I could borrow from customers to display. I had a few pieces as yet unsold, but I needed to paint a dozen or so and my mind was a blank as my canvas.
Then I came up with a way to break through "painter's block." I simply primed the pump of creativity by doing something. I sketched anything and everything in the room.
Within an hour or so, I had more ideas than I could ever produce. I had tapped into the source of inspiration by hitting it with faith and action.