What happens to your brain when you smell?
Smell is an extremely direct sense, but one that often is ignored until you pick up on something you really like – or dislike – the smell of. Aromatherapy is the practice of introducing essential oils of scent into the body to provoke a positive reaction, which can include inducing sleep, reducing anxiety and giving your more energy.
The cycle of scent:
Your nose detects scent molecules in the air as you inhale them. All volatile solids give off small and easily evaporated molecules called esters, and it’s these that transfer the smell to you. Esters can be made artificially, but the most powerful are normally natural occurring.
At the top of your nasal passages are special neurons roughly the size of a postage stamp. These are the only neurons in your body that come into contact with the air and much like the interior of the rest of your nose, include small hairs on called cilia. Cilia traps and binds scent molecules to trigger the neuron and cause the reaction. As the neuron reacts, you perceive the smell and then a reaction can happen.
The second pathway a smell can reach your sensory neurons is through the mouth. A channel connecting the roof of the throat to the nose absorbs esters that are released as a result of you chewing, which is why taste and scent are so linked.
Once you smell something, a reaction is triggered. This can include producing certain hormones and emotions, depending on how the scent neuron and your brain activity reacts to it. The part of the brain that recognises scents is linked to that where emotional memories are stored – and so all can be accessed with certain fragrances entering the body. Clinical studies into essential oils show that scents can influence weight loss, increase cognitive function, and even assist in releasing emotional trauma.
What scents triggers what reactions depends on the ester molecules and the aldehydes (components of these) that are present within them. For example, powdery scents are calming to the central nervous system and cardamom stimulates the brain to receive new knowledge. It’s easy to see, therefore, how scent can have such a huge impact on our moods, feelings and mental abilities!
When it comes to aromatherapy usage to help encourage a better quality of sleep, there are several reactions that you may wish to provoke, and many to avoid! Lavender and vetiver both ease anxiety and brain activity, allowing you to fall asleep quickly without focusing too much on your thoughts. Bergamot softens emotions and balances them, and marjoram relaxes muscles and joints. All can help you fall asleep easier and for longer, but the choice of which to use should be made based on you, your body and your sleep situation.