"So, despite what you read in the papers and in the brain-based education
literature, neuroscience has not established that there is a sensitive
period between the ages of 4 and 10 during which children learn more
quickly, easily, and meaningfully. Brain-based educators have uncritically
embraced neuroscientific speculation."
The brain-based art education course I just took never suggested any such
thing, or for that matter, most of what this writer says brain-based
education is about.
here's another site with a very brief explanation of Sperry's split brain