Illustration by James Taylor

Thanks to Colleen Walsh and the Harvard Gazette for this:

What the nose knows

Experts discuss the science of smell and how scent, emotion, and memory are intertwined — and exploited

“… I carried to my lips a spoonful of the tea in which I had let soften a bit of madeleine. But at the very instant when the mouthful of tea mixed with cake crumbs touched my palate, I quivered, attentive to the extraordinary thing that was happening inside me.”

It’s a seminal passage in literature, so famous in fact, that it has its own name: the Proustian moment — a sensory experience that triggers a rush of memories often long past, or even seemingly forgotten. For French author Marcel Proust, who penned the legendary lines in his 1913 novel, “À la recherche du temps perdu,” it was the soupçon of cake in tea that sent his mind reeling.

But according to a biologist and an olfactory branding specialist Wednesday, it was the nose that was really at work.

This should not be surprising, as neuroscience makes clear. Smell and memory seem to be so closely linked because of the brain’s anatomy, said Harvard’s Venkatesh Murthy, Raymond Leo Erikson Life Sciences Professor and chair of the Department of Molecular and Cellular Biology. Murthy walked the audience through the science early in the panel discussion “Olfaction in Science and Society,” sponsored by the Harvard Museum of Natural History in collaboration with the Harvard Brain Science Initiative.

Smells are handled by the olfactory bulb, the structure in the front of the brain that sends information to the other areas of the body’s central command for further processing. Odors take a direct route to the limbic system, including the amygdala and the hippocampus, the regions related to emotion and memory. “The olfactory signals very quickly get to the limbic system,” Murthy said.

But, as with Proust, taste plays a role, too, said Murthy, whose lab explores the neural and algorithmic basis of odor-guided behaviors in terrestrial animals…

Read the whole story here.