Some years ago I participated in a study where I lied down in an MRI machine and had to navigate in a video game maze. (Custom Half-Life 2 level, IIRC.)

Every 60 seconds or so I'd be teleported to a fresh location in the maze and given an instruction like "find the green door". I have no idea how I did compared to the other participants, but I found the maze/task to be both difficult and not at all fun.