Sight, smell, hearing, taste and touch – you know them as the traditional five senses.
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 in, they reveal some of the natural beauty and wonder that surrounds us.
What all the senses have in common is that they are processed through the brain. In fact, everything we see, hear, feel, smell and taste is perceived, and many would even argue created by – our brains.
That’s right: it’s our brains that can translate tiny, invisible airborne molecules into the smell of baked bread or a stinky sock. Our brains can convert pressure waves or vibrations into the sound of a loved one’s whisper or distant thunder. Our brains can also weave the visible light portion of electromagnetic radiation into a beautiful mountain or the glow on our mother’s face. And our brains can recognize the infrared part of that same electromagnetic radiation as the warmth we feel when we sit by a burning fireplace. It’s pretty amazing.
In the latest season of the “Chasing Life” podcast, which began this week, we will explore many of the 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 an opportunity to combine that with another love: journalistic storytelling. And what I have heard, seen, smelled, tasted and felt has been quite remarkable.
Our five traditional senses may seem simple, but they really are not. Each is multifaceted and nuanced, with many variations between 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 further broken down into pressure, temperature, tactile sensations, and pain. And we are still in the process of learning how it all works.
It was only last year, in 2021, that two scientists, working separately, shared the nobel prize for medicine for their work in identifying a sensor on the nerve endings in our skin that responds to heat and other sensors that respond to pressure. And this year alone, researchers published an article describing some of the possible neural underpinnings of pleasurable sensations such as hugs and caresses.
Also, the traditional five are not the only senses we have. It may surprise you to learn that we have at least seven, maybe eight. You’ll learn more about the other secret senses most humans possess in this season of “Chasing Life.”
In addition, we will examine what happens when people do not have a meaning or a component of a meaning. We have an episode of prosopagnosia, commonly called face blindness, a condition in which people can see faces but cannot recognize them, sometimes even members of their own family. And we will learn how people in the deafblind community have created a language to help them communicate better.
We’ll also delve into synesthesia, when two senses combine to create a unique “combined sense,” such as colored hearing, where certain sounds cause colors. You will learn why synesthesia occurs and how the experience is so inherent to the individual that many who suffer from it do not realize (for a long time) that others do not perceive the world in the same way.
We’ll also take a deep dive 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 conditions such as post-traumatic stress disorder and depression.
We kick off the season with an interview with award-winning science journalist Ed Yong. He is the author of a new book, “A World Immense: 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 well-being. The phenomenon is called the environment, a concept pioneered in 1934 by Baltic German 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 environment, beyond the scope of what we humans can know for sure. If you’ve ever wondered what it would be like to socialize by scent like a dog, use echolocation to navigate like a bat, feel the magnetic pull of the earth to migrate in the right direction like a bird, or discern your surroundings through electricity like an eel. You won’t want to miss this conversation.
Ed told me, “I start the book with this thought experiment, to imagine that you’re sharing a room with an elephant and a bee and a rattlesnake, a spider, a bat. … They could all be in the same physical space, but they would have radically different experiences of that space. The rattlesnake will be able to feel the body heat of the animals around it; the elephant could make low infrasonic noises that other creatures could not hear. A dog in that space would be able to pick up so much scent…that his animal companions couldn’t. So each of us is trapped in our own sensory bubble and perceiving only this thin slice of the fullness of reality.”
What’s really amazing, Ed said, is that every one of those living creatures, including us, thinks we’re getting a complete picture of what reality is.
“I am sitting here in this room and I do not feel that my perception of the world is incomplete. I am not sitting here marveling at the gaps in what I am perceiving. But this feeling of having it all is an illusion, and it’s an illusion that all animals share,” she said. “It tells us that even the most familiar parts of our world are full of unknown and extraordinary things.”
Ed delves into these mysteries, into the different environments of the animals, and brings them to life for us. You can listen to my full conversation with Ed Yong here.
Join us this and every Tuesday on “chasing life” As we embark on an exploration of the senses and how they bring the world to life for us, so that we can live our best lives in the world.