They are meant to protect us from danger. They help us find food and potentially even a mate. They create order in the events of the world around us, and if we are properly tuned, they reveal some of the natural beauty and wonder that surrounds us.
The thing that all the senses have in common is that they are processed by the brain. In fact, everything we see, hear, feel, smell and taste is perceived by — and many would say established by — our brain.
It’s true: it’s our brain that can transform tiny invisible molecules suspended in the air into the smell of baking bread or a stinky sock. Our brain can transform pressure waves or vibrations into the sound of a loved one or a distant clap of thunder. Our brain can also weave the visible light part of electromagnetic radiation into a beautiful mountain or the glow on our mother’s face. And our brains can recognize the infrared portion of that same electromagnetic radiation as the warmth we feel when sitting near a burning fireplace. It’s quite incredible.
In the new season of the “Chasing Life” podcast, which started this week, we will explore many mysteries of the senses.
I’m a practicing neurosurgeon and my first love has always been the brain, but reporting on this season’s stories was a chance to combine that with another love: journalistic storytelling. And what I heard, saw, smelled, tasted and felt was quite remarkable.
Our traditional five senses may seem simple, but they really aren’t. Each is multifaceted and nuanced, with many variations among humans.
Take touch, for example. Some people need to be touched and others much less. And far from being a single sense, touch can be broken down into pressure, temperature, tactile sensations and pain. And we’re still learning how it all works.
Also, the traditional five senses are not the only senses we have. It might surprise you to learn that we have at least seven, maybe eight. You’ll learn about the other secret senses that most humans possess in this season of “Chasing Life.”
Additionally, we’ll look at what happens when people don’t have a meaning or a component of a meaning. We have an episode of prosopagnosia, commonly known as face blindness, a condition in which people can see faces but cannot recognize them – sometimes not even their own family members. And we’ll learn how members of the deafblind community have created language to help them communicate better.
We will also delve deeper into synesthesia, when two senses blend together to create a single “combined sense”, such as colored hearing, where certain sounds elicit colors. You will learn why synesthesia occurs and how the experience is so inherent in the individual that many who have it do not realize (for a long time) that others do not perceive the world in the same way.
We’ll also delve into the promise of psychedelics, which distort the senses and disassociate us from our familiar way of being and can be used to treat mental health issues, like post-traumatic stress disorder and depression.
Animals and their umwelten
We kick off the season with an interview with award-winning science journalist Ed Yong. He is the author of a new book, “An Immense World: How Animal Senses Reveal the Hidden Realms Around Us”.
Ed explains how all creatures, not just humans, live in their own “sensory bubble” through which they experience a slice of reality – the very specific slice of reality that happens to be crucial to their survival and their well-being. The phenomenon is called the umwelt, a concept pioneered in 1934 by German Baltic biologist Jakob von Uexküll.
Ed takes us on a fascinating journey through the many mysterious senses of the animal kingdom that exist outside of our own umwelt, beyond the scope of what we humans can know for sure. If you’ve ever wondered what it could be like to socialize by scent like a dog, use echolocation to navigate like a bat, feel the earth’s magnetic pull to migrate in the right direction like a bird. or discern the environment via electricity like an eel, you won’t want to miss this conversation.
Ed said to me: “I start the book with this thought experiment, to imagine that you share a room with an elephant and a bee and a rattlesnake, a spider, a bat. … You could all being in the same physical space, but you would have drastically different experiences of that space.The Rattlesnake will be able to sense the body heat of animals around it;the Elephant might make low infrasonic rumbles that other creatures cannot. couldn’t hear. A dog in this space would be able to smell so much…that his animal companions couldn’t. So each of us is trapped in our own sensory bubble and only perceives that thin slice of the fullness of reality.
What’s really amazing, Ed says, is that every one of these living creatures, including us, thinks we’re getting the full picture of what reality is.
“I’m sitting here in this room, and I don’t feel like my perception of the world is incomplete. I’m not sitting here marveling at the gaps in what I perceive. But this feeling of understanding everything is such an illusion, and it’s an illusion that all animals share,” he said. “It tells us that even the most familiar parts of our world are full of unknowns and extraordinary things.”
CNN Health’s Andrea Kane contributed to this report.