Yes, now I'm reading about it a bit, and repetition (usually being a critical part of what makes something a piece of music to begin with) seems often cited as an important piece of it.

[there's this interesting book] (https://books.google.com/books?hl=en&lr=&id=4a6cAQAAQBAJ&oi=fnd&pg=PP1&dq=info:qZDte-d77AMJ:scholar.google.com&ots=w6GMO6z3_V&sig=N3I6G9Z3lKo-7nDoteWXTRE0Jww#v=onepage&q&f=false) (by a psychologist who studies music perception) that seems to make this hypothesis very clearly, that music is essentially about repetition, and the occurrence of earworms is specifically related to this quality. (i just read the first few pages and skimmed through it, looks interesting though)

but then why don't we just-as-easily get spoken phrases as earworms? on your explanation, you'd think it would be just as common to have a line of shakespeare or a piece of poetry or something lodged in your mind's ear, but it really just happens with music.

i think there's something special here that has to do with music specifically. dunno what that is.

"intrusive imagery" i.e. visual imagery is indeed something that happens, though it's probably generally considered pathological

https://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0018113

[link to the paper directly] (https://www.ucl.ac.uk/icn/sites/icn/files/brewin10.pdf)

i would submit that "earworms" are special less because of hearing/audition, but because of something to do specifically with music. (i don't know what that would be, doubt anyone does)

the "mirror neuron" is one of these neuroscience facts that has a whole mythology built up around it, way more speculation and hypothesis and.. conceptual confusion.. than actual grounded facts and evidence.

we know that there are certain neurons that activate both when the animal performs some motor act, and when it sees the same/similar act performed. these are the prototypical mirror neurons discovered by Rizzolati and Gallese (edited to correct) et al back in the 80s and 90s. these seem to be a distinct class of neurons that are not in themselves necessarily part of the basic mechanisms for performing those motor acts.

later, in humans, there have been fMRI results showing that the same/similar areas (certainly not at the resolution of "neurons", which fMRI cannot reveal) are activated by e.g. being-in-pain and by seeing-pain, or by being-disgusted and seeing-disgust. the "mirror neuron" language was then extended to these observations, though it's not been demonstrated that they are in fact similar phenomena.

in fact i tend to doubt it. think about the fact that many acts or cognitive/emotional states might be a bit invariant to "who has it", especially when it comes to recognition or comprehension. like speaking a word versus hearing a word: in both cases, surely there are common mechanisms engaged that have to do with comprehending the word. But it's not a matter of "mirroring" the word somehow, at least not in the sense of mirror neurons as they were classically described.

with that in mind, sure: if we damage your "disgust" center in the brain, you might not be able to recognize disgust in others, but you might also be unable to experience disgust. so it's not that you've lost empathy - it's that you are now "agnosic" for disgust. it has nothing really to do with "mirror neurons" or any similar concept - it has to do with the ability to recognize or represent certain states or phenomena.

So with pain, similarly, perhaps if you lose the ability to experience pain you might become less sympathetic to others being-in-pain (since you can't imagine what that state is like). but again, it doesn't necessarily have anything to do with a "mirror system for pain", which may not even be a distinct thing that exists in the brain.