Certain smells can repel or attract, bring to mind emotionally charged memories or guide our behavior unconsciously. While some find the smell of some cheeses revolting, others will appreciate its creamy and delicious taste. So just how does the olfactory system work, and can the loss of sense of smell assist in diagnosing diseases?

In this episode, cognitive scientist and empirical philosopher Ann Barwich shares what she has learned from experts in neuroscience, psychology, chemistry, and perfumery when it comes to smells. Ann says that scents, unlike visual images, can be unpredictable and limitless. 

Learn how our olfactory system works not only as a map but also as a measuring device, detecting and analyzing both simple and complex odors.

Do you think that the boundaries between the sciences and the humanities are ripe for disruption?

Absolutely. In fact, I really think these silos need to be torn down. I'm not the first one saying that, of course. My hero is Patricia Churchland who is a philosopher and actually is one of the most neuroscientifically informed philosophers there is. I took a lot of my inspiration from her because what she's been doing is absolutely radical. So, she said, instead of treating philosophy as timeless, thinking about the mind just through the mind itself, we have a revolution in neuroscience. The 20th century has revealed things about the brain and how the brain creates mind that should prompt us to rethink our initial categories for psychology.

What are the differences between the visual and scent palette ranges? 

And this is why smell is so fascinating. With colors, you've got a visible range of electromagnetic wavelengths, but you don't have any new colors. So, there's a biological timeline of what we can see. With smells, we can actually synthesize new molecules with novel odors. Molecules that have never existed on Earth, which we still can smell. We don't have to evolve new receptors. Plus, they might have qualities that are not known in nature, that might not smell like anything known in nature. So, this is why perfumers play almost with an unlimited pallet. The question is, how does the mind know what these chemical features mean? Well, that's the prize question at the moment. 

Do people experience odor blindness, the same way we experience color blindness?

[Ann] One of my favorite examples is the aroma of corked wine. And that's caused by a molecule called TCA. There are some people who are anosmic, so they can't perceive that particular molecule. They never have a bad bottle of wine in their life! 

[Greg] I should save the corked ones for when I have them over, right?

How does the nasal pathway explain how we lose our sense of smell and taste when we contract Covid-19?

First, when you sniff, you inhale. You've got this air stream coming up your nose. That's what we usually think smelling is. But we also have retro-nasal smell where you chew molecules, the aromas, hey travel basically through the back of your throat, up to your nose. That's retro-nasal smell, and it's not quite the same. There are some interesting differences. My favorite one is the fact that coffee smells great, tastes kind of disappointing. I mean, it's bitter and not as great. Nobody says, “Wake up to the taste of coffee”. 

How did the pandemic affect the way we smell? 

The more and more we go online and everything becomes a digital presence, we're losing that connection. I noticed how much I was missing during the pandemic. When I went finally out in the summer, everything hit me. Every smell. Like you suddenly have some roasted coffee, you have some trees. The world felt richer. It felt enriching compared to just sitting in your flat where everything your nose is habituating to your surroundings.

Guest Profile

• Ann’s Profile on Smellosophy’s Official Website
• Personal Profile on What It’s Like to be a Philosopher
• Ann-Sophie Barwich on LinkedIn

Her Work

• Ann-Sophie Barwich on Google Scholar
• Smellosophy: What the Nose Tells the Mind