Scent is the sense most commonly associated with memory. We all have a great, or a gross, smell that brings us right back to childhood and all the feelings that come with it. How does that happen, though? How does the brain interpret smells and link them to good, bad, or nuanced feelings? 

A new study from the University of Rochester investigated what happens in our brain when we take in a big whiff. 

Like a painting and a symphony 

Researchers found that centrifugal fibers played a key role in how the brain interprets smells. Centrifugal fibers are a set of neural connections that carry impulses from different parts of the nervous system to the relevant sensory areas of the brain. 

They found this by creating a simulated computer model of the olfactory system, the part of our brains that deals with smell. The study found the positioning of these centrifugal fibers gave the brain two methods of interpreting smells: one is like a painting and the other one like a symphony. 

In one position, the brain basically takes a picture, like a painting or a photograph, summing up all the essential features of a smell at a certain moment to give the brain a quick and general idea of a scent. 

In the other position, the brain keeps track of the evolving patterns. It is attuned to which cells tune in and out and what becomes scant or abundant —like a symphony. This one is for delivering more detail and nuance to the brain. 

You might be thinking to yourself that you don’t smell things in two different states at different times, and you’re right. The truth is that your brain uses both of these methods at the same time to interpret smell — like listening to a symphony and looking at a painting with the same sense. 

What this teaches us about smell and more

“These mathematical models reveal critical aspects of how the olfactory system in the brain might work and could help build brain-inspired artificial computing systems,” says Krishnan Padmanabhan, senior author of the study. 

“Computational approaches inspired by the circuits of the brain such as this have the potential to improve the safety of self-driving cars, or help computer vision algorithms more accurately identify and classify objects in an image.”

If your future has a self-driving car in it, make sure to lean back, take in the new car smell, and remember how our brains interpret that smell and you might have an idea of how the car drives itself. 

Source Study: University of Rochester Medical Center Newsroom — The art of smell: Research suggests the brain processes smell both like a painting and a symphony | URMC Newsroom (rochester.edu)