This made me think of rubber duck problem solving [1][2], though it didn't mention it specifically. Talking through a problem out loud forces you to structure your thoughts in a logical way, and sometimes doing that you'll realize an obvious connection or step you missed.
[1] https://en.m.wikipedia.org/wiki/Rubber_duck_debugging
[2] http://hwrnmnbsol.livejournal.com/148664.html