How to Rewire Your Brain & Learn Faster: The Science of Neuroplasticity and Neuromodulators with Dr. Michael Kilgard

This episode features Dr. Michael Kilgard, a leading expert in neuroplasticity, discussing the brain's remarkable ability to change throughout life. Historically, it was believed that only young brains were highly plastic, but Dr. Kilgard's groundbreaking work in the late 1990s demonstrated that the adult brain can undergo massive rewiring under specific conditions. His research revealed that the precise release of neuromodulators like acetylcholine, norepinephrine, serotonin, and dopamine is key to unlocking this adult plasticity. More recently, his lab has focused on vagus nerve stimulation as a method to precisely control neuromodulator timing, leading to therapeutic applications for conditions such as tinnitus, stroke, and spinal cord injuries.

The discussion delves into the differences between developmental plasticity (birth to ~25) and adult plasticity, emphasizing that while the young brain is a "sponge" absorbing every detail, the "first six years" concept is an oversimplification, and a long window for learning persists. A critical distinction is made between "real" and "artificial" experiences, particularly concerning modern technology like video games and social media. Kilgard argues that artificial environments lack the rich "statistics of the natural world" and can manipulate reward systems, potentially leading to overstimulation of neuromodulator pathways without the integrated sensory feedback crucial for healthy brain development and generalization of skills.

The episode highlights that every experience, from bedtime stories to walks in the park, contributes to brain wiring, underscoring the importance of diverse, real-world engagement for children. For adults, the implication is that intentional engagement with novel, challenging, and rewarding activities, especially those that trigger neuromodulator release, can drive significant brain change. The cautionary tale of overstimulation, whether from excessive screen time or illicit drugs, suggests that constantly pushing neuromodulator systems might diminish the brain's responsiveness to natural, everyday experiences, potentially leading to issues like depression and anxiety.

Dr. Kilgard's work has profound implications for understanding learning, longevity, and brain health, challenging long-held beliefs about the fixed nature of the adult brain. The conversation extends to philosophical considerations, referencing Ralph Waldo Emerson's views on the judicious use of books and the value of personal experience over passive consumption. This perspective encourages a balanced approach to learning and engagement, advocating for humility, adaptability, and the pursuit of genuine, multi-sensory interactions with the world to foster a brain that is not only capable but also eager to explore and adapt.

His work showed that if specific neuromodulators, meaning acetylcholine, norepinephrine, serotonin, or dopamine, are triggered to be released in the adult brain, you can achieve massive rewiring of brain circuits and learning, even as an adult.

The idea that the brain can change is a new idea. We used to think everything was hardwired, and you are the way they are, and nothing can change.

But now we can, real time, watch these new connections and imagine that there's not hundreds of them, there's not thousands of them, there's not millions of them, there's not billions, but there's trillions of new connections every second of your day, are trying to decide, should I strengthen this one, should I weaken this one, or should I leave them the same?

The fact that the young brain is a sponge, and that every little background sound, little clicking sound, road noise, all those things, have the potential to impact the way the brain is wired is a cautionary tale.

No one formative experience is going to ruin some kid's life. And I think that's a little bit relieving as well.

My concerns about video games and other things like that are these could be really detrimental, because they don't have the statistics of the natural world.

When they all get separated, and the touch doesn't have anything to do with the sound, and the sound doesn't have anything to do with the sight or the smell, there's a potential for them all to sort of drift off on their own and not be integrated in a way that I think is most helpful.

Books well-used are among the best of things, and poorly used among the worst.

Consistency is the hobgoblin of little minds.

The problem is, we don't know what the long-term consequences are of having over and over and over activation of that pathway.