Why Does Smell Bring Back Memories?



Edited by- Oishiki Ganguly 


University students, all over the world, are dearly missing their campuses and dorms during the pandemic. Our campuses are places that have seen all our lowest and highest moments and our dorm rooms have been our places of refuge in all kinds of situations. Going back to the campus a few months ago, to stuff pack up my dorm life, felt a lot more melancholic than I had imagined. Entering my dorm room was already making me teary-eyed, when I was instantly met with the familiar smell of my dorm room and that brought back vivid and clear memories of all the times I had spent there: like trying to study, gossiping with friends and mostly watching Netflix on sleepless nights.


The memories really came rushing back and I was overcome with lots of emotions that I had experienced in that room. Even faces of all my friends, who I hadn’t seen for months, came back to me almost like flashbacks. While I packed up my entire college life in two huge suitcases for what seemed like an eternity, these memories lingered on in my mind. It seemed as if these memories were more clear and vivid than the ones we usually have while going through old pictures or while listening to old music. But, were the memories really different or did I just feel as if they were more vivid? In any case, there seems to be some sort of connection between memories and smells. Being a psychology student, I decided to read about this connection and investigate if there really is one. Thanks to all the research paper reading skills that I have acquired at Ashoka, I was able to find some possible theories that would explain why this happens.


Looking at this dorm room example, there seems to exist a very strong relationship between the olfactory cue, which is the smell in my room, here at play that managed to help me recall memories with such vividness. Turns out, this phenomenon has been named the Proust phenomenon named after the French novelist Marcel Proust. Proust had written, in one of his novels, about his experience of eating madeleine and being reminded of his childhood days. From this description, comes the Proust phenomenon which is described as rushing back of autobiographical memories due to the presence of a strong sensory stimulus. There are certain theories that psychologists have come up with to explain why this happens.


Encoding Specificity is one such phenomenon which can be used to explain why the olfactory stimulus was able to bring back memories. Encoding Specificity is when with the storage of information certain contextual conditions also get stored along with it. This means that the odours present in at the time of memorizing information acts as a retrieval cue later to bring back the memories. This means that while I was in my dorm, talking to my friends the smell present there became a cue and when I was later presented with the cue, when I went back to the dorm, the memories came surging back. Researchers Aggleton and Waskett (1999) also conducted a similar experiment and concluded that participants in their study who had the same odour present while memorizing and retrieving some information did better while retrieving it.



Another aspect which can explain why this phenomenon is the neural pathways that connect our sensory organs and parts of the brain that perceive them. Odour information travels through the central olfactory pathways which travel all the from the sensory nerves to the parts of the brain and these pathways are anatomically different from other sensory items. One extensive study on the neuroanatomy of the olfactory nerve, which carries information from our noses to the brain, by Elizalde et al. (2018), talks about these pathways. They have described these pathways in detail and have written that “The main central cortical structures of olfaction include the primary olfactory cortex, the anterior olfactory nucleus, the olfactory tubercle, the amygdaloid complex…Secondary central structures of olfaction include the hippocampus, hypothalamus, thalamus…”


This might not make much sense at first, however, neuroscientists have time and again discovered that both amygdala and hippocampus in the brain have a role to play in the formation of emotionally relevant memories. This indicates that the passing of neural olfactory pathways through these brain parts could be one of the reasons for olfactory stimulus being so effective at bringing back emotional autobiographical memories and why the smell of the room freshener in my dorm room took me back to my time on campus.


The moment I entered the room and took a breath in, I was reminded of a time which was almost a distant memory now, and I could easily recall all the details absolutely clearly. This sudden recall of memory, which is also known as, Proust effect, as I mentioned, could have been a result of both, encoding specificity and the passing of olfactory neural pathways through the amygdala and the hippocampus and there could also be many more theories at play here which haven’t been researched upon yet.


So, this research ended up into some interesting insights about memories and how they can be brought back to life. Apart from bringing back nostalgia, certain techniques can be devised using this research to help in many memory-related issues. It points towards the possibility of better retrieval for our exams and important tests by being surrounded by similar sensory cues at the time of memorizing and recalling. This technique might also be helpful for people suffering from different kinds of amnesia and can be used as a tool to help them retrieve information. Researchers can also look at such cues for understanding flashbacks in trauma survivors and helping them by avoiding them.