Why PBL is Good for the Brain
The news coming in about neuroplasticity—the finding that the brain changes dramatically in response to experience—continues to amaze scientists and intrigue the general public. But the news hasn’t yet impacted education, partly because the gap between teaching methods and neuroscience can’t yet be bridged, and partly because our profession, though relying on the brain more than any other, can’t quite fit a standardized curriculum into a new paradigm that has made obsolete the old view of the brain as hard wired and immutable, or even as the repository of a fixed IQ.
However, maybe we need to take a leap of faith and make best guesses about the relationship between brain function and classroom instruction. My guess is this: Based on preliminary findings in neuroscience, I suggest that PBL fits perfectly with what we can surmise about encouraging optimal brain function.
Just to clarify, I’m not talking about cognitive studies showing that working memory—the ability to manage facts and short term responses—can be marginally improved with practice. These studies aim us at better test taking, but little else. The real prize is increasing creativity, problem solving, and fluid intelligence, which is the ability to adapt to new experience. This ability to innovate in response to environment, in fact, seems to be the main message of today’s brain science. It’s what we do as humans. For example, imagine our Neanderthal ancestors around the fire 200,000 years ago. Somewhere in their brains lurked the ability to do AP Calculus, program an Android phone, or parse a presidential debate. What’s lurking in the minds of the 1.5 billion children alive today that can help them manage their adult world? Inquiring teachers should want to know.
So, teaching students in a brain-friendly way is crucial. Here are reasons that I believe PBL supports the brain:
Rich experiences create dense neural networks. Of course, walking alone down a deserted street at 3 a.m. in a dangerous city is a rich experience, especially if you’re being followed. But in the classroom, PBL is designed to offer an educationally rich experience: A complex problem to be solved; multiple inputs and potential solutions; a team-based environment that relies on extensive collaboration; adult interactions; and exhibitions that stretch students. Contrast that with coverage, front of the room instruction, and even low level activities aimed at solving known problems. In workshops, I urge teachers to aim for the top of the new Bloom’s Taxonomy, the sections focused on critical inquiry and creativity. The brain is drawn to those sections as well.
Neural development depends on feedback loops. The brain has an intelligent system for improving itself. Neural development takes place in areas of the brain most useful to solving the problem at hand. Most of the research these days focuses on understanding the pre-frontal cortex—the site of execution, planning, and problem solving. This is a tricky area, because if you present a problem to a student that is too difficult, it activates the hind brain and the stress response. But an appropriate, engaging, manageable challenge is exactly what the brain likes. The brain, in fact, loves novelty. PBL is an excellent method for inviting novel solutions to authentic problems—a combination that feeds the brain and speeds connections.
Risk and failure feeds the brain. Neuroplasticity tells us that neurons form alliances, hook up, unhook, and reform their networks in milliseconds, always on the hunt for the right response or a new solution. In fact, it seems apparent that without challenge, or in the presence of low level facts, the brain gets bored. Working memory is crucial to us on a daily basis, but if that’s all we used, life would be a monochrome. On the other hand, using a design mentality, with the constant goal of getting better, more thoughtful, and finding more elegant solutions, is second nature to the brain. Quality PBL makes failure, risk, and improvement an integral part of the process of learning. No wonder that, with PBL, teachers see extremely high levels of student engagement.
Integrating thinking and feeling fits with the design of the brain. The old view that cognition—the ability to think—is separate from the ability to feel is not supported by current neuroscience. The brain operates as in integrated organ, processing emotions and thinking together in the amygdale, limbic system, and other parts of the brain still under investigation. Significant evidence also exists that the heart drives brain function through nervous connections to the hind brain and cortex. This is close to the frontiers of science, so we don’t know much yet as to the exact mechanisms. But it is well established that love, care, and personal mentorship increase educational achievement. In PBL, this is critical. Basically, a teacher won’t get performance in a PBL environment without creating a culture of care and connection. In my view, this sets up the brain for learning. Without the care, the brain says, “No.”
The power of reflection. Studies show that mindfulness increases neural density as much as a multi-stimulus environment. This tells us that the brain doesn’t just respond to massive amounts of information or a super-interesting problem; in some way, it also benefits from stillness and a meditative look at its own performance. In quality PBL, reflection is critical. This includes reflective pauses in the process of a project, as students review and assesses their progress in solving a problem, as well as more in depth reflection at the end of a project. The end of the project reflection encourages students to power down and probe their development. Evidently, the brain thinks this is a good idea, too.