I hope that most teachers are aware of the importance of vocabulary on one's ability to learn new concepts (see Marzano to learn more), but I just listened to an amazing Radiolab  podcast that explores the interplay between language and thought.  Of particular interest to me was the description of how a teacher thought to teach the concept of names to a 27 year old Mayan man who had lived his entire life devoid of sound and the way that adults were reduced to rat like thinking when their brain was overhelmed.

I encourage you to listen when you get the chance....