Are you like me, in that you get powerful memories triggered by certain smells and odours? For me, the most obvious is the association of childhood freedoms in the woods with the wonderful, earthy, woody smell of patchouli oil. Often our associations are of food, as the nourishment we had as children is linked with happy experiences of pancakes or candyfloss.
Why can odours trigger such powerful responses in us? In fact, the sense of smell is closely linked to memory as well as emotion. Receptors in the nose transmit signals to the olfactory bulb, which is located in the limbic part of the brain. It is close to the amygdala, which processes emotion, and the hippocampus, which is responsible for associative learning. It will come as no surprise that babies recognise their mothers’ odour, especially that of breast-milk, and this contributes to mother-baby bonding, ultimately even to a child’s development.
The association of our mum’s odour with feelings of warmth and nourishment probably provide the first link of odour and emotion. Mammals are the only animals known to attribute associative meaning to odours. When you first smell a new scent, you associate it with an event, a person, or perhaps a specific moment. It is the conditioned response that triggers memories: your brain makes a link between the smell and the memory. When areas of the brain are damaged, it becomes a problem to identify smells, such as for people with Alzheimer’s disease and dementia. Odour therapy is actually used to try to unlock their memories.
One reason it can be hard to identify an odour is that we don’t always have the vocabulary to describe it. Learning the terminology and vocabulary of odours was one of the keys to my memorising the odour profiles of about 2000 ingredients when I was training to be a perfumer. Without being able to describe and ‘log’ a scent in my memory bank – i.e. identify it, it would have been impossible to write a single formula! It is thought that it doesn’t help us that normally odours are learned very gradually. Also, when you think about it, objects we experience visually are labelled from an early age, e.g. ‘car’ or ‘dog’, but smells are not labelled in the same way, so we don’t build up our odour vocabulary.
What is probably true, though, is that our mums, through having made apple crumble every Sunday, or roast beef with Yorkshires, have provided us with some lovely odour associations that help to make us who we are. So remember that this Mother’s Day, on 30th March, and treat your mum to something she can appreciate the scent of for a long time to come!