Ben Goldacre's 'bad science' column in the guardian has been going after this for years. It's good, old fashioned campaigning journalism, and after five years might actually be having some effect. As he puts it:
'The very same person who tells your child that blood is pumped around the lungs and then the body by the heart, is also telling them that when they do The Energizer exercise then “this back and forward movement of the head increases the circulation to the frontal lobe for greater comprehension and rational thinking”'.[http://www.badscience.net/?p=613]
On the other hand, a glance at google shows how deep the problem goes: http://www.google.com/search?q=%22brain+gym%22+site%3Agov.uk