The researchers found that for every one-point increase in both olfactory identification and sensitivity scores, there was a significant and meaningful reduction in frailty status. The study can't prove cause and effect, but the implication is that improvements in smell were associated with improved health status and resilience, the study authors noted.

— Read more in Loss of smell associated with frailty in older adults at UPI.

Our sense of smell is clearly a complex process; it involves hundreds of different odorant receptors working in concert. The more an odor stimulates a particular neuron, the more electrical signals that neuron sends to the brain. But researchers at UC Santa Barbara discovered that these neurons actually fall silent when an odor rises above a certain threshold. Remarkably, this was integral to how the brain recognized each smell. "It's a feature; it's not a bug," said Matthieu Louis, an associate professor in the Department of Molecular, Cellular, and Developmental Biology [at University of California - Santa Barbara].

— Read more in Researchers reveal an added layer of nuance in our sense of smell at ScienceDaily.

A team at the University of Lisbon was conducting research to map brain activity and brain response to certain fragrances, working to create a database of results that provided subjective and objective insight into human response to scents.

“The goal is, in effect, to build a database so when you have a fragrance or a blend, you can predict what the response of our customers will be,” ​said Hugo Alexandre-Ferreira PhD, associate professor at the University of Portugal.

Read more in University of Lisbon mapping brain responses to fragrance: 'Sense of smell is the most mysterious' at Cosmetics Design-Europe.

To make sense of this baffling chemistry, researchers have turned to the computational might of artificial intelligence. Now one team has trained a type of AI known as a graph neural network to predict what a compound will smell like to a person—rose, medicinal, earthy, and so on—based on the chemical features of odor molecules. The computer model assessed new scents as reliably as humans, the researchers report in a new draft paper posted to the preprint repository bioRxiv.

— Read more in AI Predicts What Chemicals Will Smell like to a Human at Scientific American.