We have all experienced it, that feeling of being transported back to another time in our lives when a certain smell overwhelms us with memories. It can take us aback and flood us with emotion. It can cause us to want to stay there in that moment for a while longer to keep remembering. The sense of smell is closely linked with memory (probably more so than any of our other senses).
A brief science lesson behind the smell connection:
Scents bypass the thalamus (whose primary function is to relay motor and sensory signals to the cerebral cortex) and go straight to the brain’s smell center, known as the olfactory bulb. The olfactory bulb is directly connected to the amygdala (a collection of nuclei found deep within the temporal lobe) and the hippocampus (a complex brain structure embedded deep in the temporal lobe which has a major role in learning and memory). This could explain why the smell of something can so immediately trigger a detailed memory or even intense emotion.
The Proust effect:
There is a passage in literature so famous that it has its own name…the Proustian moment. It is a sensory experience that triggers a rush of memories from long ago or maybe even almost forgotten. For French author Marcel Proust, who wrote these lines in his 1913 novel, “À la recherché du temps perdu,” it was the taste of cake in tea that sent his mind reeling.
“… 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 was the nose that was really at work here as we know, but this bit of literature gave us a name for that rush of emotion we get when a smell overwhelms us and transports us back in time. The phenomenon is referred to as the Proust effect.
Extensive research shows that these smell-induced memories are more emotional and evocative than recollections provoked by other sensory stimuli, such as sight or sound. They also tend to be from an earlier time, flooding your brain with memories of childhood or other feelings of nostalgia.
Maria Larsson, a researcher at Stockholm University was trained in the study of memory, but became interested in smell when she realized that “there are a range of descriptions and stories from novelists like Marcel Proust.” For visual and verbal cues, people’s memories came from their teens and 20s, as expected. But for smells, the peak was around age five. “It was really, totally clear that when they recollected a specific memory, that memory was localized to the childhood period,” she says. The memories were also more emotional and more vivid than memories brought up by visual or verbal cues.
Maybe it’s freshly cut grass that takes you back to a summer day, rain in the mountains that reminds you of camping as a young child, a certain smell from a kitchen that transports you back to your grandparents’ house during the holidays, or chlorine and swimming pools. Smells evoke memories of our long ago past.
This is not a new mechanism. This ability is often regarded as being the old, or primitive, part of the brain considering these same structures were present within the brains of the very first mammals. Acknowledging this helps us to understand why smell plays such an important role in memory and emotion.
On a more somber note, considering that our sense of smell clearly plays an important role in our psychological make-up, in addition to being one of the five ways in which we connect with the world around us, the absence of our sense of smell can have a profound impact as well. It stands to reason that losing one’s sense of smell can result in the loss of an important sentimental pathway to memories. Research has shown that loss of olfactory function can be an indicator of something far more serious. Smell loss occurs with both Parkinson’s disease and Alzheimer’s, and studies have pointed to a diminishing sense of smell being a sign of the onset of both conditions.
Smell is a potent wizard that transports you across thousands of miles and all the years you have lived. The odors of fruits waft me to my southern home, to my childhood frolics in the peach orchard. Other odors, instantaneous and fleeting, cause my heart to dilate joyously or contract with remembered grief. Even as I think of smells, my nose is full of scents that start awake sweet memories of summers gone and ripening fields far away.”– Helen Keller