Dr. Sanjay Gupta: It’s not your five senses that help you make sense of the world


Sight, smell, hearing, taste and touch: you know them as the five traditional senses.

They are meant to protect you from danger. They help us find food and potentially a mate. They create order in the events of the world around us, and when properly attuned, reveal the natural beauty and wonder that surrounds us.

What 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, and many would argue. create by – our brains.

That’s right: it’s our brain that can translate small, invisible molecules in the air to the smell of bread or a smelly sock. Our brain can convert pressure waves or vibrations into the whisper of a loved one or the sound of distant thunder. Our brain can also weave the visible light of electromagnetic radiation into a beautiful mountain or the glow on our mother’s face. And our brain can recognize the infrared part of this electromagnetic radiation as the warmth we feel when we sit next to a lit fireplace. It’s pretty amazing.

In the newest season of the “Chasing Life” podcast, which started this week, we explore many mysteries of the senses.

I’m a neurosurgeon, and my first love has always been the brain, but reporting this season’s stories was an opportunity to combine it with another love: journalistic storytelling. And what I heard, saw, smelled, tasted and felt was quite remarkable.

Our traditional five senses seem simple, but they really aren’t. Each is versatile 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 divided into pressure, temperature, tactile sensation and pain. And we’re 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 in Medicine for their work in identifying a sensor that responds to heat and another that responds to pressure in the nerve endings of our skin. And this year, researchers published a paper describing some of the possible neural bases of pleasurable sensations like petting and petting.

What’s more, the traditional five are not the only senses we have. You may be surprised to know that we have at least seven, maybe eight. You will learn more about other secret senses that most humans have in this season of “Chasing Life”.

In addition, we will analyze what happens when people do not have sense or a component of a sense. We have an episode about prosopagnosia, commonly called face blindness, a condition in which people can see faces but cannot recognize them, sometimes not even their own relatives. And we will learn how people in the deaf-blind community have created a language to help them communicate better.

We will also delve into synaesthesia, when two senses blend together to create a unique “combination sense”, such as color hearing, where certain sounds produce colours. You will learn why synesthesia occurs and how the experience is so unique to the individual that many sufferers 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 separate us from our familiar way of being, and which can be used to treat mental health conditions like 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, “The Terrible World: How Animal Senses Reveal Hidden Realms All Around Us.”

Ed explains how all creatures, not just humans, live in their own “sensory bubble” through which they experience a part of reality – the specific part of reality that is essential to their survival and well-being. The phenomenon is called umwelt, 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, beyond the reach of what we humans outside of our umwelt can know for sure. If you’ve ever wondered what it might be like to socialize by smell 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 sense electricity like an eel. , you won’t want to miss this interview.

Ed told me, “I start the book with this thought experiment, to imagine you’re sharing a room with an elephant and a bee and a cricket, a spider, a bat. … You could all be in the same physical space, but you would have vastly different experiences of that space. The snake will be able to sense the body heat of the animals around it; the elephant can make low infrasounds that other creatures cannot hear. A dog in that space would be able to pick up so much scent…that its peers couldn’t. So each of us is trapped in our own sensory bubble and perceives only this thin slice of the fullness of reality”.

What’s really incredible, Ed said, is that every single one of these living things, 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 surprised by the gaps I’m seeing sitting here. But that feeling of getting it all is such an excitement, and it’s an excitement that all animals share,” he said. “It tells us that even the most familiar places in our world are full of unknown and extraordinary things.”

Ed dives into these mysteries – the different umwelts of animals – and brings them to life. You can listen to my full interview with Ed Yong here.

Join us this and every Tuesday”Chasing life” as we set out to explore how the senses and the world bring us to life so that we can live our best lives in the world.