I have this book, and if you're learning to draw, I highly recommend it.
Contrary to what Geez might think, the concept of left brain vs. right brain has little to do with motor skills -- at least when talking about thought process. The book tries to push all symbology and logic, a left hemisphere function, out of the drawing process.
What people don't realize is that while their brain is developing, when you're a small child, you are already starting to associate objects with symbols, long before observation kicks in. If the learning-to-draw process is interrupted in childhood (which it often is after First Grade), the existing symbology carries through to the adult stage of development. That is why many un-artistic adults still draw trees like lolipops, and houses like square with triangles on top. And so, even if an adult tries to draw something he sees, he's not really looking. That is because he's drawing an object (a symbol from the left side of the brain) as opposed to the form (right side)
Very good book! I've used it, and I enjoy it still.