I encountered a structure which I didn't encounter before, which is shown in the following image.
It seems like a circle within another circle. The task started with the 'outer' circle being highlighted. When scrolling up, the separate circles remained visible (tube in tube?), but after a while vanished and took over the inner circle.
I'm a bit uncertain what the best approach is in this case. Often there is a lot of 'junk' inside which you just have to fill up, but perhaps this is some form of strange connection between two neurons?