Having rapidly grown to more than 200 students in preschool through third grade, the school has become a kind of national laboratory for integrating cognitive neuroscience and cutting-edge educational theory into curriculum, professional development and school design.

“Schools were not applying this new neurological science out there to how we teach children,” said Lindsey Russo, whose unusual title, director of curriculum documentation and research, hints at how seriously the Blue School takes this mission. “Our aim is to take those research tools and adapt them to what we do in the school.”

So young children at the Blue School learn about what has been called “the amygdala hijack” — what happens to their brains when they flip out. Teachers try to get children into a “toward state,” in which they are open to new ideas. Periods of reflection are built into the day for students and teachers alike, because reflection helps executive function — the ability to process information in an orderly way, focus on tasks and exhibit self-control. Last year, the curriculum guide was amended to include the term “meta-cognition”: the ability to think about thinking.

“Having language for these mental experiences gives children more chances to regulate their emotions,” said David Rock, who is a member of the Blue School’s board and a founder of NeuroLeadership Institute, a global research group dedicated to understanding the brain science of leadership.

Though data is scarce, private school experts and the small number of lenders who provide loans for kindergarten through 12th grade say pre-college loans are becoming more popular. Your Tuition Solution, one of the largest lenders in this space, says demand for the upcoming year is already up: This month, the total dollar amount of loans families requested rose 10% compared to a year ago; at that pace, the company expects its total funding to rise to $20 million for 2012-13. Separately, First Marblehead, which exited the market in 2008, reentered last year as demand for loans began to rise.

Much of this demand is coming from high-income families. Roughly 20% of families that applied for aid to pay for their children’s kindergarten through 12th grade private school education had incomes of $150,000 or more, according to 2010-11 data, the latest from the National Association of Independent Schools. That’s up from just 6% in 2002-03. Those who don’t get approved for free aid, like grants, increasingly turn to loans, experts say.