There is a strange stretch of road on Interstate I-85 between exits 57 and 62 that is like no other that I have ever experienced. Rather than being utilized as a high-speed connector for traveling long distances, this five mile section of asphalt is instead used by locals to travel between the adjacent towns of Auburn and Opelika. Now there is nothing conceptually wrong with that of course; the problem is that they actually treat it as a local surface road: traveling in the left hand lane at 35 miles per hour, stopping along the way in mid route as if there are stop signs and red lights, and making frequent U-turns without whim or whether. As I was driving along this section of paradise yesterday (running late as usual and everyone in my way) I found myself impatiently tailgating a 1976 Chevy Camaro as if this somehow would miraculously cause them to speed up, or at least move over to the right. As the driver of said Camaro made his requisite unannounced U-turn across the median he downshifted, causing a puff of blue smoke to envelop my own car. Instantaneously I was transported more than a quarter of a century back in time. Memories of Yamahas and CanAms, my ’51 Chevrolet Step Side that always leaked oil but never burned it, as well as its coincident opposite: a ’78 Monte Carlo that burned oil by the quart from the day it left Detroit, but never really leaked much. Other similar associations came fast: 7 canisters of blown freon escaping into the atmosphere only hours before heading out on a twenty hour cross country adventure. The permanent black in the grooves of your hands and, somewhat inexplicably, fireworks.

Of course there is nothing unique in this phenomenon; we have all experienced the flood of memories that a smell can bring. But why is this? Technically the olfactory bulb is part of the brain’s limbic system, an area of the brain closely associated with memory and feeling. The olfactory bulb is tightly coupled with the Amygdala, which processes emotion, and the deep hippocampus, which is responsible for associative learning. So how this mechanism works is relatively clear, but just why it works the way it does is still somewhat a mystery. Smells would never trigger memories if it weren’t for a unique spin on the notion of the conditioned response. In classic conditioning, it usually takes repeated and regular exposure to a stimulus to trigger a response, with smell and memory however it seems that we only need exposure to a smell once for it to forge this relationship of powerful latent recall. Years later, when you encounter the smell again, the link is already there, ready to elicit a memory or a mood. For obvious temporal reasons, we encounter most new smells as children; subsequently odors most frequently trigger memories of our youth.

All of this is interesting of course, but what is most fascinating to me is that it also works in reverse: when I think of a rather generic and ubiquitous event from childhood (fishing, for instance) – the smells of the event are often the first thing that comes back (the sultry tang of green cattails, the sweet meatiness of worms that pervaded my tackle box, the salty flatness of Vienna Sausages doused in lake water to slough off the fat and warming in the sun) allowing a much more rich topography of the specifics of the event to emerge. Sounds come rushing back (the metallic slap of water against the hull, the incessant buzzing and crescendo of cicadas, the zip and click of the reel drag) and then finally a much greater ability to reconstruct a scene visually.

Inversely, one odor can also trigger a memory from a different but similar odor: for years after I returned from my first trip to London, the smell of a diesel engine would most often transport me immediately back to the first day I descended into the London Tube. Years later when I returned to the Underground, I was startled to find that the smell had changed; obviously what had really happened is that I had replaced one association for another. More startling though is how easily these memories can be erased. For example, when I was an undergraduate student I spent a lot of time in the Art Studios of Biggin Hall. I distinctly remember that Biggin smelled like art: turpentine, oil paint, and linseed oil: it was the smell of decades of work performed by countless students. Several years ago an extensive renovation was performed on the building, which, among other less than desirable consequences, eradicated the “art” smell completely. Until the moment I revisited the building following the renovation, I could always recall the distinct pleasant smell of Biggin. Unfortunately by somehow erasing the smell from the building, upon my return it also immediately erased it from my memory as well – conceptually I know what it is, but I can no longer recall it. Sad, truly.

Finally, for some reason as I have been working through this way-too-long ramble, I keep coming back to one of the most pervasive smells of my childhood: that of the library. After thinking through my Biggin experience – I am now all of the sudden kind of afraid to visit the library – now THAT would be one tough smell to lose. Good thing I have Google and Wikipedia, I guess – I wonder what they might smell like to young kids just growing up?