By Robert Tisserand, the Tisserand Institute

Aroma psychology is a fairly new term used to describe the effect of essential oils on the psyche. The olfactory system, which is responsible for our sense of smell, is a complex array of structures in the brain, and many of these are the same ones that process both memory and emotion. Smell is the only sense where messages pass directly to the limbic system (our emotional brain) “unfiltered” by the thalamus, which means that we have more of a visceral response to olfaction that we do to other senses. Because of this, essential oils are a powerful tool, capable of a vast array of psychological functions and benefits.

Targeted memory reactivation

One of the most interesting aspects of aroma psychology is that smelling odors while you’re asleep can be beneficial, through an evolving discipline called targeted memory reactivation (TMR). Research in Canada and Germany demonstrated that school children who used TMR remembered facts from a lesson significantly better than those who did not use it. 

While we’re asleep, our brain decides what to remember and what to forget from that day’s experiences. So, if we smell an odor during a learning experience (diffused in the classroom), and then smell the same odor while asleep (diffused in the bedroom) the same night, this prompts the brain to remember anything associated with this odor.

Olfactory conditioning

Even without sleep, we can create “anchors” using odors. For example, when you’re on vacation (and hopefully feeling good), you can try smelling an essential oil that you’re not familiar with (therefore no previous associations) several times a day. When you’re back home, you can smell this oil when you’re stressed, and your body-mind connection will remember how it felt on vacation, alleviating the stress. Use this power sparingly, however — if you smell too much, you may dilute the effect.

Furthermore, a British neurologist, Dr. Timothy Betts, used olfactory conditioning for some of his patients with epilepsy. The anchor was created by means of a relaxing, aromatic massage. After several sessions, the person would pull out the same essential oil used in the massage when they felt the aura of a seizure, and most of the time the seizure would not occur. Out of 46 participants in the study, 16 were completely seizure-free after 12 months.

Improving sleep and relaxation

People have used pleasant smells to help achieve relaxation for thousands of years. While there are no strongly sedative essential oils, most are calming. Lavender has been the subject of much research, so we understand how it works. Lavender improves sleep quality by helping people to fall asleep more readily, and by increasing delta wave activity along with the time spent in slow-wave (deep) sleep. Different lavender oil studies have shown improved sleep in hospitalized patients, the elderly, postpartum mothers, and people with mild insomnia.

Remember to use essential oils with care

There are several ground rules in aroma psychology, but the main one is that less is more. There is even research suggesting that below-threshold odors can influence our behavior, so there’s no need to overdo it. Remember that even though essential oils are made from natural materials, they still require careful handling. It’s important to gain a fundamental understanding of essential oil safety when diving in the world of aroma psychology, but if you proceed responsibly, a world of benefits awaits.