How Scents Are Hacking Your Brain

Ever smelt something that immediately transported you to a different time in your life? Whether it’s the smell of freshly baked bread from the bakery you loved visiting as a child or the potent fragrance of your boss’ perfume strutting across the room compelling you to once again ask yourself “Is this job worth it?”, scents are ubiquitous. They act as a gateway to our memories, helping us form vivid emotional connections with our past and present experiences. Whether it’s from candles, perfumes, diffusers - or even dumpsters - scents have become a means of communication. People are now willing to spend hundreds of dollars on luxury scents in the hopes of expressing their individuality in more nuanced manners. What I’ve always pondered about though is how does our brain process scents and store such an evocative impression of them? And are brands exploiting this intimate interconnection? 

Scents being marketed

Let’s explore this from a biological perspective. It all starts with, as you probably guessed, the nose. Inside our nose are several tiny receptors, each geared towards sensing specific types of odours. Once the scent molecules bind to their respective receptor - like a rocket - an electrical impulse is triggered along the nerve fibre (axon) to the brain. The impulse makes a pit stop at the olfactory bulb, required to process the smell, before heading off to the main trifecta - involving the olfactory cortex, amygdala and hippocampus. Now, instead of travelling to the thalamus like visual or auditory information, due to the strategic position of the olfactory system, information can be directly passed to the olfactory cortex and the respective parts. If the brain were an office for instance, the receptor bounded with the molecule would be a file, the olfactory bulb would act as a manager who primarily approves of the file, the olfactory cortex is the team leader who needs to recognise the file, the amygdala would be the analyst who generates an outcome from the file and finally the hippocampus would be the file cabinet organizer to carefully store the file. Harvard Medicine has a wonderful video on the subject for a deep dive.

A rough sketch of the parts of the brain involved

If the brain was an office

The fact that the olfactory system is so close to the main part of scent processing in the brain is the primary reason as to why scent driven memories are much more profound and intense, when compared to other sensory memories. We feel such memories on a deeper level when a scent is associated with them. These memories are called Proustian memories as the profound experience of scent memories are poetically put into word by Marcel Proust in the novel Swann’s Way. In his novel, there is a scene that describes the transformative experience when Marcel dips a madeleine into some linden-blossom tea and how the aroma overwhelmed him. It paved a rush of emotions in Marcel as he remembered the very specific memory of his aunt giving him madeleines dipped in lime blossom tea on Sundays in his childhood home in Combray. Hence the name Proust phenomenon. In Proustian memories the cue is smell and it triggers very specific and significant memories of a person's life – something that holds deep emotional value. If you wish to dive deeper on the Proust phenomenon, cognitive neuroscientist, Rachel Herz has an insightful article titled Scents of Time.

But it’s not just nostalgia that scents are inviting, businesses have started valuing scent as an important asset too. The intense emotional experiences that Proustian memories bring about are of utmost benefit to companies as they remind their audiences of a distinct memory - frozen in time. This is the exact reason why scent branding is becoming increasingly popular. Scents are being marketed not only as a mood-lifter but as a way of expressing individuality; which is pivotal in a society that values authenticity. Companies have understood the incredible power scents hold over us and this is evident in the data around us. According to Grand View Research, the market for candles in 2024 was at USD $14.06 billion and is projected to grow to USD $20.10 billion by 2030. Additionally, it was reported by Lifestyle Research Center that in 2022, there were more that 152,000 bottles of perfume sold in France everyday. 

Perfumes are becoming an expression of identity

Scent branding is gaining widespread popularity. Take Hyatt hotels for example. Across 300 U.S locations, the same omnipresent fruity yet musky aroma tactfully lingers. Our brain now associates that scent with the opulence of the brand. The scent invokes luxury, relaxation and timeless elegance. Similar notes of blueberry and vanilla elsewhere might just immediately transport you to the hotel lobby – longing for another vacation.

Smells have been shaping our experiences more quietly than we think; and definitely more than we give them credit for. Scents aren't simply background anymore – they are a reflection of us and our identity. Thus, the next time any of you Quirks out there smell something familiar, I urge you to pause and sniff. There might be a whole story yet to unfold. 

Final Thought: What you smell today could be your most cherished memory tomorrow.

So, what scents bring back the most vivid memories for you?