Sandeep Robert Datta is a Professor of Neurobiology at Harvard Medical School and a leader in the field of olfactory research. His life’s work has been exploring the biology of the olfactory system. His exploration of the multiple areas of the brain that are involved in the act of smelling helps to explain why smell training works. When Chrissi met up with Bob, she asked about the role of brain plasticity in smell training.

Studies of olfactory training demonstrate that people perform consistently better in smell tests than people who don’t practise smell training. It appears that smell training helps to re-establish neural networks. How does this plasticity work?

In the context of neuroscience, plasticity refers to the ability of neural networks in the brain to change through growth and reorganisation. The brain can be rewired to function in a way that differs from how it previously functioned. The brain is an organ that is designed to keep learning all through life, so the ability to change and develop is key to survival.

Bob briefly outlined the role of different parts of the brain in the function of smelling. Signals received in the olfactory bulb are sent to the hippocampus, the part of the brain related to memory. The hippocampus builds maps of memory and creates relationships to space, objects, time. These individual moments of memory are sent on out to other areas for the rest of the brain to learn from. This is how we become more experienced in dealing with any given situation.

The olfactory or piriform cortex receives signals for smell perception. This registers how smells relate to each other and relate to other experiences. The piriform cortex is nestled next to the hippocampus. These areas and all the complex signals emanating from them, are constantly updating experiences. 

In Bob’s view, the brain is a place built for life long learning. He sees it as the natural set up to benefit from smell training. His research demonstrates that smells must be properly mapped into the broader library of smell experiences. This is what your hippocampus is naturally built to do, so give it the experience it needs by regularly and mindfully stimulating it with smell training.

The whole system is designed for episodic memory, and it has to keep updating itself. The piriform has circuits that remember recent experience, so that experience has to be regularly repeated to have a benefit. Smell training will quite quickly be forgotten if it’s not kept up daily.

In the opinion of the neuroscientist, the more smell training you can do, the better. Keep at it!

You can listen to the entire conversation on our podcast here.

Read Bob Datta’s insight into how Covid-19 induces smell loss and why some people take so long to recover.

Read the neurobiolgy view of smell, emotion and memory.

June 07, 2022