In this episode, a renowned neurosurgeon shares what he has learned in decades of working to restore ailing brains. His new book covers a vast range of neuroscience. Our dilemma was what to pay attention to in all those options. In a sense, that is always the human situation. We are capable of conscious processing of approximately 200 bits per second (bps) of information. Our unconscious brain deals with as much as 11 million bps.

At The People’s Pharmacy, we strive to bring you up to date, rigorously researched insights and conversations about health, medicine, wellness and health policies and health systems. While these conversations intend to offer insight and perspective, the content is provided solely for informational and educational purposes. Please consult your healthcare provider before making any changes to your medical care or treatment.

How You Can Listen

You could listen through your local public radio station or get the live stream Saturday, May 16, 2026, at 7 am EDT on your computer or smart phone (wunc.org). Here is a link so you can find which stations carry our broadcast. If you can’t listen to the broadcast, you may wish to hear the podcast later. You can subscribe through your favorite podcast provider, download the mp3 using the link at the bottom of the page, or listen to the stream on this post starting on May 18, 2026. (This show originally aired April 25, 2025.)

The Power of the Unconscious Brain

Our senses feed us a tremendous amount of information all the time, but we don’t have the bandwidth to pay attention to more than a small fraction of it. That’s where the unconscious brain is so valuable, juggling millions of bits of information while we focus our conscious attention on what seems important.

One surprising outcome of the research on how our brains function is a re-assessment of what is going on when people are unconscious. For centuries, doctors thought there was really no brain activity while a person was comatose. Then, a few decades ago, a scientist was recording the brain waves of a patient in a coma. The activity was very peculiar, as if the person were watching a ball being lobbed back and forth across a tennis court. In actuality, a television set in the room was broadcasting a world championship match between Roger Federer and Rafael Nadal. The neuroscientist recognized that this individual was following the match and was not nearly as deeply unconscious as had been thought. Further research showed that this kind of unconscious brain activity is not uncommon. It may hold keys to determining who has the best potential for recovering from their coma.

Freud and the Unconscious Brain

If you hear the term the unconscious mind, you may think of Sigmund Freud. He really popularized the concept that some very important brain activity takes place outside of our conscious awareness. It still has a powerful influence on our behavior.

By the way, if we recognize that our conscious attention is indeed a limited resource (200 bps, remember), we won’t try to multitask. Humans actually aren’t very good at multitasking; instead, we switch our attention from one thing to another. Some people can do that fairly easily, but for most of us, it is less effective than staying focused.

Three Stages of Brain Development

Evolution likes to build on what it’s already got in place, so it shouldn’t surprise us that we can track three different evolutionary stages to our human brains. The reptilian brain came first, of course, and is there as a base, operating mostly on reflex. It’s definitely an important part of the unconscious brain.

The mammalian brain brings in emotions. The hormone oxytocin is relevant for this discussion. It is critical for birthing and nursing young. As it turns out, oxytocin can also be put to other uses, such as bonding mates together and creating friends.

Finally, we have the primate part of our brain. We humans, like other primates, can exercise empathy because our mirror neurons allow us to relate to another creature’s experience. In fact, mirror neurons were discovered by scientists studying macaques and eating gelato. Listen for a great story!

Speaking of empathy, we wondered about empathy fatigue. We started hearing about empathy fatigue during the COVID pandemic, when healthcare providers were overwhelmed by extreme demands with inadequate support. Research shows that “constant, repetitive exposure to the pain of others leads to empathy fatigue.” Lack of empathy can lead people to do terrible things.

Wonders of the Unconscious Brain

Our brains are full of clocks. To some extent, these are shaped by how we use them. Musicians who play percussion instruments can perceive time differences of just a few hundredths of a second. All of us are entrained to a 24-hour a day cycle, whether we observe sunrise and sunset or not. But if we are deprived of connection with that cycle, our internal clocks can’t keep good time, and our brains may get far off track.

What About Premonitions?

Some people think premonitions are a fantasy. Yet this is another area where our unconscious brain may be more capable than we imagine. Dr. Hamilton describes an experience in the Swiss Alps where he and his wife had a choice of which path to take down from the summit. One appeared to be a shortcut, and they did have some time constraints. But as soon as they had taken a few steps that direction, he had a premonition of something terrible. They took the other path and learned later that there had been a landslide on the shortcut that would have swept them helplessly down the mountain.

According to Dr. Hamilton, some people have the ability to influence the output of random number generators. Those of us who can’t may wish to reject that idea, but it has been documented. The Princeton Engineering Anomalies Research lab has run many studies demonstrating an impact on random number generations, not to mention remote viewing. In this way, some of the hidden power of the unconscious brain appear as cerebral entanglements, analogous to quantum entanglements at the sub-atomic level of matter.

This Week’s Guest

Dr. Allan Hamilton, MD, FACS, is a neurosurgeon who has specialized in treating brain tumors. His extraordinary journey from janitor to Harvard-trained neurosurgeon is just the beginning of his remarkable story. A decorated Army veteran, he now holds four professorships at the University of Arizona and has been recognized as “One of the Leading Intellects of the Twenty-First Century.” As the only American honored with the Lars Leksell Award for pioneering scientific discovery in stereotactic neurosurgery, Dr. Hamilton’s groundbreaking work has revolutionized the field. He has had a life-long interest in the application of computer technologies to enhance surgical care and reduce avoidable medical adverse events. In addition, he has served on two White House Advisory Committees under two presidential administrations.

Allan Hamilton, MD, FACS

His expertise extends beyond medicine, having studied creative writing under Rod Serling and serving as a senior medical consultant for Grey’s Anatomy for nearly two decades. Dr. Hamilton’s seven non-fiction books have garnered numerous awards and international translations, offering insights that have inspired leaders across various fields. Dr. Hamilton’s 7th non-fiction book is Cerebral Entanglements: How the Brain Shapes Our Public and Private Lives.

The People’s Pharmacy is reader supported. When you buy through links in this post, we may earn a small affiliate commission (at no cost to you).

Listen to the Podcast:

The podcast of this program will be available Monday, April 28, 2025, after broadcast on April 26. You can stream the show from this site and download the podcast for free.

Download the mp3, or listen to the podcast on