Where does it say that in post one?
Sorry but I thought you may have seen the reference to his jointly written book.
I have several close relatives in my family that, are also medical professionals, have read this book have enjoyed it as much as I did, none of them picked up on the speech centers part you refer to, and they wouldn't of held back from telling me about anything they thought wasn't kosher about any of the book's contents.
Like I said I will ask around and I'm asking around because I can't argue the case for a subject I only have a rudimentary knowledge about, but I can find out.
ippy