Here is a sentence from Making Sense of Japanese by Jay Rubin:
They are just part of the world's most clunky writing system, and a writing system cannot cause a language to be processed in a different part of the brain any more than it can force it to some other part of the body (excepting, of course, Lower Slobovian, which is processed in the left elbow).
It seems that there is a joke or word play involved, the very point of which I cannot get at. I tried to search
Slobovian + elbow but failed to find any information on their connection. Is it just the author's original invention?