It happens for examples in a shutdown, when I cannot find words anymore and there is this weird feeling spreading all over and the body is just "taking over", and it doesn't need to be only head banging but the body itself getting hit, but it is no more a conscious action taking place and it is this frustration that you cannot talk to a person at that moment, because the mind has shut down and is "blanking", but you want to communicate.
Secondly external sensory overload.
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English is not my native language, so I will very likely do mistakes in writing or understanding. My edits are due to corrections of mistakes, which I sometimes recognize just after submitting a text.