Inner Cosmos with David Eagleman

What is depression? Why are brains able to slip into it? Is depression detectable in animals? Do animals have options beyond fight or flight? And what does any of this have to do with measuring depression medications in city water supplies, reward pathways in the brain, the prevalence of tuberculosis, and zapping the head with magnetic stimulation? Join today's episode with David Eagleman and his guest -- psychiatrist Jonathan Downar -- for a deep dive into the brain science behind depression and what new solutions are on the horizon.

Why can you hear some sounds two different ways, depending on which word you’re looking at? Why do electrical outlets sometimes look like a face? How can you have rich visual experience with your eyes closed? Are some crosswalk buttons fake? Why are some pictures interpretable only once you’ve been told what to look for? And although brains are often celebrated for their parallel processing, what should they really be celebrated for? Tune in to learn what happens when the raw facts of the world collide with your expectations.

When he was a child, Eagleman fell off a roof and time seemed to run in slow motion. When he became a neuroscientist, he grew curious about the experience and collected hundreds of similar stories from others. But is it true that your brain can actually see in slow motion, like Neo in the Matrix? And how would you test that? Hear how he dropped volunteers from a tower to put the science to the test, and what the answer reveals about our perception, memory, and experience of the world.

What would it be like to have a vastly better memory than you do now? What if you could remember what you were wearing on any day a dozen years ago? Or who you were with, what the conversation was, and whether it rained? Would it be a blessing or a curse? And if you’re forgetting a lot of your life, what might you do to better remember it? Join Eagleman with actress Marilu Henner, one of only dozens of people in the world diagnosed with highly superior autobiographical memory.

When you imagine something -- like the sun peeking over a mountain during an early morning rainstorm -- do you see it with rich visual detail, or instead with very little internal picture? In an earlier episode we tackled the spectrum of visual imagination, from hyperphantasia to aphantasia -- and in this episode we dive even deeper with guest Joel Pearson to surface the most surprising differences between people's internal lives. How does your experience differ from other people's, and how does your brain cobble together the skills you have to accomplish what you need?

Why do you see a unified image when you open your eyes, even though each part of your visual cortex has access to only a small part of the world? What is special about the wrinkled outer layer of the brain, and what does that have to do with the way that you explore and come to understand the world? Are there new theories of how the brain operates? And in what ways is it doing something very different than current AI? Join Eagleman with guest Jeff Hawkins, theoretician and author of "A Thousand Brains" to dive into Hawkins' theory of many models running in the brain at once.

How do you define what things are living and dead? You might look at a sprinting cheetah and say it's clearly alive, whereas a chunk of rock is not -- but where do we draw the line? What might we expect extraterrestrials to look like, and would we even have the capacity to recognize them? And what does any of this have to do with Frankenstein, ancient Greek philosophers, or the possibility of finding a cell phone on Mars? Join Eagleman with guest Sara Walker, theoretical physicist at Arizona State University and author of the book “Life as No One Knows It”.

Do brains time travel? What is a prediction error? What does any of this have to do with the 2008 crash of the economy, how we keep internal price tags, or a rational approach to drug addiction in society? Join Eagleman to learn how your 3-pound universe spends its whole existence nailing down choices.

When you make a decision about what food to order, what's happening in your brain? How do you clinch long-term decisions, like hitting the gym instead of doomscrolling? And what does any of this have to do with the ancient Greeks, alien hand syndrome, and constraining a president who wants to launch a nuclear bomb? Join Eagleman this week and next to discover how your brain weighs alternatives and nails down decisions.

From the brain’s point of view, what is humor? When something is funny, why do we breathe in and out rapidly? Do other animals laugh? Why do most jokes come in threes? What do mystery novelists, magicians, and comedians have in common? Could AI be truly funny? Join Eagleman this week to appreciate the tens of reasons and millions of years behind the tickling of your neural pathways.

What does neuroscience have to do with investment, and what does that have to do with Isaac Newton, the Dutch East India company, Kodak, the way zebras herd, our emotions, and almost 200 cognitive biases? Join Eagleman with guest Mark Matson, whose new book The American Dream dives into the cognitive illusions we face when trying to make investments.

You know that moment in the horror movie where the monster is coming closer, but the movie star doesn't see it? Why does that drive you crazy, and what does that teach us about brains? What is theory of mind, and why is it so important for everyone from poker players to conmen to stage magicians to novelists? Join us this week to dive into a fundamental skill of human brains -- and the question of whether current AI has any ability to simulate other people's minds.

Is your notion of yourself built on narrative that may or may not be accurate? If someone told you an entirely false story about yourself, could you come to believe it? What does that have to do with six people who spent over a decade in prison together for a crime they didn't commit? Join Eagleman for part 2 of some mind-blowing conclusions about your account of your own life.

Why did lions look so strange in medieval European art? What does this have to do with Native American folklore, eyewitness memory of a car accident, or what a person remembers 3 years after witnessing the 9/11 attack on the World Trade Center? And what does any of this have to do with flashbulb memories, misinformation, and the telephone game that you played as a child? Join Eagleman for part 1 of an astonishing journey into what we believe about our memories.

What does the Baader-Meinhof Group, a West German terrorist group from the 1970s, have to do with the front of your brain, attention, salience, and synchronicity? And why might you soon hear about the Baader-Meinhof Group again, not for political reasons, but for reasons to do with your own neural networks? Join Eagleman for a dive into how we take in the world around us -- and how we get fooled about the frequencies of events.

Why are the majority of stock trades decided by algorithms at timescales we can scarcely conceive of? What is it like to have the speed and power of a computer, and to be dealing with slow humans? Why are movies compelling, given that they are just a series of photographs flashed rapidly? And what happens if we someday discover planets with creatures who operate on totally different time scales? Join Eagleman this week for a deep dive into speed: the speed at which we operate, the speed at which our machines operate, and what this all means for the future as the divergence grows larger.

We're the single species who composes symphonies, erects skyscrapers, builds computers, and regularly gets off the planet. But how did human intelligence evolve from our ancestors in the animal kingdom? And now that our species is scintillatingly shrewd, what does a knowledge of our road mean as we work to build intelligence artificially? Join Eagleman this week with Max Bennett, an especially smart human who illuminates a path through the 600 million year story of brain power in his book "A Brief History of Intelligence".

Why are conspiracy theories a natural output of the brain? What do they have to do with puzzle-solving, cognitive dissonance, ingroups/outgroups, and storytelling? If you hear an unlikely explanation for something, what are effective and ineffective ways to assess it? Join Eagleman to understand from the point of view of the brain why conspiracy theories have always been so pervasive in human societies.

Did magicians discover tricks of the mind centuries before neuroscientists? Why can’t you see what they’re doing right in front of you? How do magicians steer your attention or appear to read your mind? Dive into the trapdoors of the human brain which allow the mind to get fooled. Join Eagleman with several guests: magician Robert Strong and cognitive neuroscientists Stephen Macknik and Susana Martinez-Conde.

If you could get a kiss from your favorite celebrity, how long would you want to wait before receiving it? And why do things seem less meaningful or joyful over time than they were at the beginning? What does any of this have to do with Netflix releasing all the episodes of a new show at once, or why companies come out with new and improved products every year, or why French revolutionaries wanted to make a week five days long instead of seven? Join Eagleman and cognitive neuroscientist Tali Sharot to find out why everything dulls with time and what we can do to recover the shine.