NEWS Mental Health News New Research Explains Why Scent Triggers Such Powerful Memories By Lo Styx Lo Styx Lo is a freelance journalist focused on mental health, sexual wellness and patient advocacy. She is based in Brooklyn and can be found on the internet @laurenstyx. Learn about our editorial process Updated on March 22, 2021 Fact checked Verywell Mind content is rigorously reviewed by a team of qualified and experienced fact checkers. Fact checkers review articles for factual accuracy, relevance, and timeliness. We rely on the most current and reputable sources, which are cited in the text and listed at the bottom of each article. Content is fact checked after it has been edited and before publication. Learn more. by Daniella Amato Fact checked by Daniella Amato Daniella Amato is a biomedical scientist and fact-checker with expertise in pharmaceuticals and clinical research. Learn about our editorial process Share Tweet Email Print Hinterhaus Productions / Getty Images Key Takeaways A recent study explored the power of scent in triggering memories.The findings suggest this ability comes from the connection between the olfactory system and the hippocampus in the brain.This could help us better understand broader brain dysfunction and advance intervention and treatment. Certain smells, both good and bad, have a way of transporting us back to specific moments in our lives. Likely, you can even call one to mind right now. A new study published in Progress in Neurobiology explores the power of scent in triggering memories, suggesting this ability comes from the connection between the olfactory system and the hippocampus in the brain. As part of the limbic system, the hippocampus serves the most primitive aspects of our brain, like memory, pleasure, pain, and motivation. It plays a critical role in our ability to form new memories and acts as a sort of temporary storage and command center for their organization. A better understanding of the olfactory system could help us better understand broader brain dysfunction and advance intervention and treatment. What the Study Shows The new study set out to better understand the human olfactory system and its connection to memory. Lead researcher Christina Zelano, PhD, and the study's team of researchers set out to better understand the profound role our sense of smell has in connecting us to our memories. With the help of neuroimaging and intracranial electrophysiology, researchers were able to directly compare the ways in which the hippocampus functions across human sensory systems. This comparison revealed that, at rest, the olfactory system is more strongly connected to the hippocampus networks than the other systems of sight, sound, taste and touch. The Scent-Brain Connection Evolutionarily speaking, any animal's sense of smell is a critical survival tool, Zelano says. We are constantly monitoring the air around us with every breath, sending information directly to our nervous system. Leela Magavi, MD Scents that soothed children can continue to alleviate stress and anxiety for the entirety of adulthood. Scents that triggered anger and sadness can continue to result in negative emotions for years to come. — Leela Magavi, MD Zelano describes this system as both fascinating and under-appreciated. "It is our oldest sensory system, evolutionarily speaking, and the one located deepest in our brains," she says. "It is a complex system, with many parallel paths delivering odor information simultaneously to many brain areas milliseconds after we sniff... This powerful sensory system is critical to our human experience. Yet it is perhaps the most poorly understood system compared to other human sensory systems," says Zelano. Our sense of smell is also profoundly connected to memory. Studies have shown that odor serves as a stronger trigger than any other sensory cue for recalling personally meaningful memories. "Smell and emotion intertwine and can be saved in the brain’s software for years," says psychiatrist Leela Magavi, MD. "Scents that soothed children can continue to alleviate stress and anxiety for the entirety of adulthood. Scents that triggered anger and sadness can continue to result in negative emotions for years to come." "We can also use our sense of smell to very quickly assess complex aspects of our environment: good and bad smells can guide where we go, what we eat, who we like to be with, where we are comfortable or ill-at-ease," she says. "And memory is a critical part of all of these decisions and more." What Is Memory? Smell Loss and Brain Dysfunction With the COVID-19 pandemic, smell loss has become an epidemic of its own. It's been estimated that, of people with mild cases of COVID-19, about 86% lose some or all of their ability to smell. Within six months, 95% of those people will have regained their sense of smell. Beyond being recognized as a symptom of COVID-19, smell loss is highly correlated with depression and can have immense negative effects on quality of life, Zelano points out. Christina Zelano, PhD Sometimes the sense of smell isn’t fully appreciated until it is lost, and then its profound place in our everyday experience becomes starkly apparent. — Christina Zelano, PhD As we age, our sense of smell gradually begins to fade, which directly impacts our ability to taste and enjoy food. An inability to smell can also affect our ability to sense danger, like failing to notice that something is burning. At the same time, smell loss appears to implicate broader brain dysfunction and even neurodegenerative diseases. Dysfunction in the olfactory system is common and serves as an early symptom of conditions like Alzheimer's and Parkinson's diseases. However, Zelano is careful to point out that smell loss is not indicative of having either of those diseases in the future. A better understanding of conditions like these calls for a better understanding of the facets of the olfactory system and how odors affect the human brain—for example, its aptitude for evoking vivid memory. "By advancing the basic neuroscience of olfaction... we hope that this will lead to better interventions and treatments of smell loss, and perhaps even other neurological diseases," Zelano says. What This Means For You We often take our sense of smell for granted. But scent is an incredibly powerful trigger for memory recall, as the human olfactory system is linked directly to the most primitive parts of our brain. The Psychology of Forgetting and Why Memory Fails The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page. 5 Sources Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Zhou G, Olofsson JK, Koubeissi MZ et al. Human hippocampal connectivity is stronger in olfaction than other sensory systems. Prog Neurobiol. 2021;201:102027. doi:10.1016/j.pneurobio.2021.102027 Dhikav V, Anand K. Hippocampus in health and disease: An overview. Ann Indian Acad Neurol. 2012;15(4):239. doi:10.4103/0972-2327.104323 Herz R, Eliassen J, Beland S, Souza T. Neuroimaging evidence for the emotional potency of odor-evoked memory. Neuropsychologia. 2004;42(3):371-378. doi:10.1016/j.neuropsychologia.2003.08.009 Lechien JR, Chiesa‐Estomba CM, Beckers E, et al. Prevalence and 6‐month recovery of olfactory dysfunction: a multicentre study of 1363 COVID‐19 patients. J Intern Med. 2021;290(2):451-461. doi:10.1111/joim.13209 Hüttenbrink K-B, Hummel T, Berg D, Gasser T, Hähner A. Olfactory dysfunction. Deutsches Aerzteblatt Online. 2013;110(1-2):1-7. doi:10.3238/arztebl.2013.0001 See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Speak to a Therapist Online Advertiser Disclosure × The offers that appear in this table are from partnerships from which Verywell Mind receives compensation.