http://www.sciencecodex.com/when_it_comes_to_food_obese_womens_learning_is_impaired-137641 (http://www.sciencecodex.com/when_it_comes_to_food_obese_womens_learning_is_impaired-137641)
Whoahhhh.
It's too bad that this study wasn't conducted in children, of course-- but the implications alone ought to give ANY educator using food incentives a reason to re-think that practice, given childhood obesity rates.
(I have no idea how robust the experimental design, and yeah-- 18 is a small N for this kind of thing, but still-- it's an arrow in our collective quiver when it comes to getting food rewards out of classroom spaces.)