Khan's hideous little creatures are not unlike the annoying snippets of pop songs that get lodged in your head and won't go away—so much so that German music fans have adopted the term "ohrwurm" (earworm) to describe the phenomenon.
Recently a Dartmouth research team applied the tools of science to this universal malady and ascertained that it's all caused by the rostromedial prefrontal cortex (RPC), a part of the brain whose duties include remembering melodies and, unfortunately for earworm sufferers, playing them back ad nauseam.
In January, Dartmouth College's Center for Cognitive Neuroscience released a study identifying the RPC as the source of this internal torment, according to Sam McManis of the San Francisco Chronicle. The RPC is especially equipped to "remember and appreciate music," in the words of lead researcher Petr Janata—even if it's endlessly repeated drivel like No Doubt's "Hey Baby," or "Seasons in the Sun," Terry Jacks' insipid hit from the 1970s. This neural playback isn't "necessary for human survival, yet something inside us craves it," Janata told the Associated Press.
There is no known cure for the earworm phenomenon, but anecdotal evidence indicates that repeated playings of the offending tune at very loud volume may help as a sort of musical aversion therapy. So does drowning it out by playing something with real musical substance, at least temporarily. There is even a website devoted to earworms, but none devoted to the cure. The search continues.