I found this.
http://i1204.photobucket.com/albums/bb410/raykongs/Capdidacticmemory_zps7bdc6c5e.jpg
I do think this is something that has been pushed much more in recent times. Caps intelligence I think could be equivalent to Aquaman's tp in the sense that some writers may not know he has it and is rarely refered to.
When I first started reading Cap I had been doing it for several years and I don't think I read anywhere in comics or bios that it enhanced his mind. This seems to be a modern phenomenon, there is also a reference to his intelligence in Secret Avengers were its stated by Beast that Cap is a super soldier that can master any weapon in seconds.