People have been mucking around with external electric fields to modulate neural activity for literally millennia! A Roman physician used electric fish to treat gout and headaches.
Obviously not (see numbers I crunched above) but....
a) The long and fascinating history of brain zapping only starts with fish. There were all kinds of cockamamie inventions in the 1700s-1900s, some of which were a lot of closer to this purported effect. There was also a lot of interest in using weak electric currents to improve sleep c. 1965-1975 ("electrosleep"). Anyway, I just thought it was a cool fact worth a mention.
b) It was actually an Atlantic Torpedo (a ray), which is still stronger than this. Weakly electric fish might actually be in the ballpark: they only emit about a volt--and in freshwater.
