The other day as I was walking through the city, trying to find a quiet place to study, I stopped in front of a bakery when the buttery, warm, and slightly sweet aroma filled my nose. Suddenly, I was transported back in time: I was seven years old, standing in my grandmother’s kitchen, watching her roll out dough. I recalled the joy and anticipation I felt while watching the dough rise in the oven and the same sweet aroma that filled my nose as the bread turned golden brown.
If you’ve ever caught a whiff of something that instantly reminded you of a specific time or place, you’re not alone. This is called the Proust phenomenon. The term originates from Swann’s Way (Proust, 1928), in which the smell of a madeleine biscuit dipped in linden tea triggers intense joy and a vivid recollection of the author’s childhood. This experience laid the foundation for the hypothesis that odor-evoked memories tend to be more emotional than those triggered by other sensory stimuli.
Dr. Rachel Herz and her colleagues at Brown University conducted one of the earliest studies to test this hypothesis in 2002. They found that a group of five women exhibited greater brain activity when smelling a perfume associated with a personal memory compared to when they smelled an unfamiliar scent. Remarkably, the familiar scent even triggered more brain activity than simply seeing the perfume bottle (Herz and Schooler 2002).
More recently, in a 2018 study, researchers asked 170 participants to smell different odors and record the memories that surfaced. They then asked questions about each memory, such as whether it was clear or fuzzy and emotional or neutral. The results? Smells triggered clearer, more emotional memories than looking at pictures. The effect was even stronger in older adults, who were able to recall much earlier memories through scent than with visual cues. (de Bruijn and Bender 2018).
Science behind smell
So how do smells trigger such strong emotions and memories? Unlike most of our senses—such as vision, hearing, and touch—which first pass through the brain’s “switchboard,” known as the thalamus, smell takes a unique shortcut. As odor molecules enter our nose, they bind to corresponding olfactory receptors, triggering an electric signal that travels to the olfactory bulb, the brain’s first processing center for smell. Instead of being rerouted through the thalamus, this signal takes a VIP pathway straight to the hippocampus, the brain’s memory storage center, and the amygdala, which processes emotions. This explains why certain smells can instantly transport us to a specific moment in time, evoking emotional memories. Some scientists believe this goes back to evolution, as early humans relied on smell to detect danger, find food, and recognize their environment.
Why odor memories are important
Scent-triggered memories aren’t just about nostalgia—they can also have real benefits. For individuals with Alzheimer’s disease or dementia, scent-based memory recall has been explored as a therapeutic tool to help retrieve lost memories and improve cognitive function (El Haj et al.2017). On a broader level, smell influences our emotions and well-being. Studies have found that scent-evoked memories are often more positive than those triggered by other senses, helping to boost mood and self-esteem (Herz 2016). Smell is also deeply tied to identity and relationships—certain scents remind us of home, family traditions, and moments that shaped us. Even beyond personal experiences, scents can be cultural markers, connecting us to our heritage and shared history.
Unlike a photo or a song, a scent doesn’t just remind us of the past—it pulls us right back into it. Whether it’s the comforting aroma of home-cooked meals, the nostalgic scent of an old book, or the fragrance of a loved one, these memories shape our identities, connect us to our past, and remind us of the moments that matter most. Perhaps that’s why simply catching a familiar scent can feel like an embrace from time itself—an unexpected, yet welcome reminder of the stories we carry within us.
Sources:
de Bruijn, M. J., and Bender, M. 2018. Olfactory cues are more effective than visual cues in experimentally triggering autobiographical memories. Memory 26:547–58.
El Haj M, Gandolphe MC, Gallouj K, Kapogiannis D, Antoine P. 2018. From Nose to Memory: The Involuntary Nature of Odor-evoked Autobiographical Memories in Alzheimer’s Disease, Chemical Senses. 43(1): 27–34
Herz RS , Schooler JW. 2002. A naturalistic study of autobiographical memories evoked by olfactory and visual cues: testing the Proustian hypothesis. Am J Psychol. 115:21–32.
Herz, R. S. 2016. The role of odor-evoked memory in psychological and physiological health. Brain Sci. 6:22.
Great post! I liked how you included why odor memories are important, as I would have never thought that this could help in memory recall for people who suffer from dementia. I have experienced memories being triggered due to certain smells, but I didn’t know that smell essentially took a shortcut to the hippocampus and the amygdala for this to occur. I also found it interesting how smells could influence our emotions. Next time I feel a switch in my emotions, I’m going to pay attention to see if the odor in my environment had something to do with it.
I really liked this post, it’s crazy how a smell can take you right back to a specific moment like that. The part about the brain’s shortcut for smell was super interesting and made a lot of sense. It’s cool how you connected that memory at the bakery to the science behind it. Made me think of some old memories I haven’t thought about in a while.