My ex-wife doesn't have internal dialogue. Instead, when she is thinking through something she has images in her head of shapes morphing. She told me that she felt having an internal monologue would be horribly annoying and horribly slow.
Did her brain get bricked every time she saw something of high enough quantity?
I remember having more visual thinking until preteen, but then it gradually turned into a monologue and I hate it, because I can tell I got slower at mundane thoughts even if it helps me think through complex stuff.