For me, there are few scents more provocative that the smell of newly-cut grass at the beginning of the growing season. While the sound of a lawnmower has few, if any, connotations for me, the scent of cut grass in May transports me instantly back to exam season: the relentless passage of time; the stress and anxiety of the unknown; the growing sense of foreboding… Conversely, the smell of a particular citrus perfume brings an instant sense of calm and wellbeing. A popular scent used by young people in Spain in the 1980s, it transports me instantly to the sun-drenched plains of Andalucía, where I lived and worked in my early twenties: the merciless sun, the distant sound of barking dogs and the tranquillity of the olive groves instantly emerge, like old friends, from the mists of time. The sense of smell is deeply entwined in our emotional memory, rather more, so it seems from recent research, than any of the other four senses.
It is perhaps significant that the eye harbours only two different cell types, the rods and cones, that are capable of sensing light. By contrast, humans have in excess of 400 different olfactory receptors in the nose. Together these are able to distinguish between an estimated one trillion different chemical structures, each with their unique odour. The importance of such exquisite discernment, lies in the role played by the sense of smell in defining identity: unique chemical signatures in the amniotic fluid enable the growing fetus to recognise the mother after birth, primarily through the sense of smell, bringing both calm and reassurance. The reason that smells can evoke such powerful emotions may lie in the fact that neurons involved in sensing smell link directly to the olfactory bulb and then to centres in the brain involved in memory: a rather less circuitous route than sounds and sight appear to take.
Such insights into the biology of smell and the neglected role it plays in memory and emotional regulation have helped illuminate the understanding and treatment of some psychological issues: could it be, for instance, that certain smells may serve to trigger the vivid flashbacks characteristic of PTSD? Conversely, could the power of smell be exploited therapeutically, the use of coffee grounds, for instance, to bring a person back to the safety of the present moment after reliving traumatic memories. And for those experiencing the debilitating impact of panic attacks, might early exposure to a scent that evokes comforting memories of safety help divert them from the well-trodden path of panic, transporting them instead to the plains of Andalucía or beyond…
(Image courtesy of Anthony Tran and Unsplash)