Your Nose Is Doing More Than Smelling

Olfaction, Brain Training and the Emerging Science of Scent

You open a bottle of rosemary essential oil and inhale.

We might describe what happens next quite simply:

You smell rosemary.

But neurologically, something considerably more interesting has begun.

Of all our senses, smell has an extraordinary relationship with the brain. Olfactory pathways interact closely with regions involved in memory, emotion and learning — which may help explain why an aroma can sometimes evoke a person, place or moment before we have consciously worked out why.

Increasingly, researchers are asking another fascinating question:

What happens when we deliberately exercise our sense of smell?

Could smelling — noticing, distinguishing, remembering and repeatedly experiencing different aromas — be considered a form of sensory enrichment for the brain?

Welcome to the fascinating world of olfaction.

From the nose to the brain

When aromatic molecules enter the nose, they interact with olfactory receptors high within the nasal cavity.

Signals travel through the olfactory system to the brain, including the olfactory bulb and cortical regions involved in processing odour.

But olfaction doesn't exist in isolation.

The networks involved have important relationships with areas concerned with memory, emotion, learning and decision-making.

This is one reason scent can feel so extraordinarily evocative.

A particular perfume can remind us of someone we haven't thought about for years.

Woodsmoke can transport us to an autumn evening.

Lavender might remind one person of a beloved grandmother and another of a childhood garden.

The aroma hasn't contained the memory.

Our brain has made the association.

And that distinction is important.

Rosemary, lavender and an intriguing question

The relationship between aroma and cognition has interested researchers for decades.

In 2003, researchers including Mark Moss studied 144 healthy adults who were exposed to rosemary aroma, lavender aroma or no aroma while completing cognitive assessments.

Differences were observed between the groups in aspects of cognitive performance and mood.

It was an intriguing finding.

But science rarely gives us definitive answers from one study.

Instead, good research creates more questions.

What exactly is happening when we smell?

Are particular aromatic compounds important?

Does expectation influence the experience?

What happens when exposure is repeated?

And perhaps most interestingly:

Can the olfactory system itself be trained?

Smell training

Olfactory training traditionally involves repeatedly and deliberately smelling a selection of different odours over a period of time.

It has been studied particularly in people experiencing impaired smell function.

But researchers have increasingly begun exploring something broader:

olfactory enrichment.

Rather than simply asking whether someone's ability to detect an odour improves, researchers have begun investigating whether repeated olfactory stimulation might also be associated with changes elsewhere in the brain.

That brings us to a particularly interesting experiment.

Seven scents. Six months.

In research published in 2023, adults aged between 60 and 85 were assigned either to an olfactory-enrichment intervention or to a control condition.

Participants in the enrichment group were exposed to a rotating selection of seven different scents while they slept, with one scent presented for two hours each night over six months.

The researchers assessed cognition and also used brain imaging.

They reported a significant difference between groups in a verbal learning and memory measure and changes involving the left uncinate fasciculus.

That name might sound rather removed from the world of the apothecary.

But it is fascinating.

The uncinate fasciculus is a white-matter pathway connecting parts of the temporal lobe with regions of the frontal cortex. Those interconnected regions have roles in processes including memory and emotion.

The findings don't tell us that smelling essential oils prevents cognitive decline.

They don't demonstrate that aromatherapy prevents dementia.

And they certainly don't give us permission to put a bottle of rosemary beside the bed and promise a better brain.

What they do provide is another intriguing piece of evidence in a much larger field examining olfaction, sensory enrichment and neuroplasticity.

Neuroplasticity: a brain capable of change

For a long time, the adult brain was often imagined as relatively fixed.

We now understand that the brain retains an ability to adapt in response to experience.

This is known as neuroplasticity.

Learning a skill, repeatedly practising something and encountering new sensory information can influence neural networks.

And this gives us an interesting way of thinking about smell.

Perhaps smelling doesn't always have to be passive.

There is a difference between an aroma simply existing in a room and deliberately engaging with it.

Consider what happens when you smell something unfamiliar and ask:

What can I detect?

You smell again.

Floral?

Woody?

Citrus?

Earthy?

Familiar?

Where have I experienced this before?

Can I distinguish it from another aroma?

Can I remember it tomorrow?

Suddenly we are doing considerably more than simply saying:

That smells nice.

We are paying attention.

We are discriminating.

We are retrieving memories.

We are creating associations.

We are learning.

The apothecary as a place of sensory learning

This is one of the reasons I find the emerging research around olfaction so exciting.

An apothecary has traditionally been somewhere we encounter plants through their properties and uses.

But perhaps a modern apothecary can also become somewhere we rediscover our senses.

Not everything needs to happen quickly.

We can stop.

Smell.

Notice.

Compare.

Remember.

Return.

That philosophy has become an important part of The Living Apothecary Method™.

And it is also why our new Elixir Experience begins with the sense of smell.

Why Elixir begins with scent

Elixir is a twelve-month guided wellbeing experience within The Living Apothecary.

It isn't about promising a transformation in twelve easy steps.

It is about becoming curious about ourselves again.

And when I considered where that journey should begin, I kept returning to something wonderfully simple.

The nose.

Our first Elixir gathering begins in the apothecary with scent.

We aren't trying to diagnose ourselves from the essential oil we choose.

Nor are we claiming that a particular aroma will somehow reveal what the body needs.

Instead, we begin by noticing.

What happens when I slow down enough to smell deliberately?

Which aromas do I recognise?

Which do I find difficult to describe?

Can I distinguish one botanical from another?

Does an aroma evoke a memory?

What happens when I return to it later?

It becomes an exploration of attention, sensory awareness, memory and curiosity.

And over twelve months, we can return to those observations.

Because wellbeing isn't always about adding another thing to our lives.

Sometimes it begins by noticing what is already there.

Try it: smell without the label

Choose three safe, familiar aromatic materials. These might be herbs from the garden, citrus peel, spices from the kitchen or essential oils you already use appropriately.

If using essential oils, smell from a scent strip or another appropriate indirect method rather than repeatedly inhaling closely from the bottle.

Don't look at the names.

Take one aroma at a time.

Smell briefly and then move it away.

Ask yourself:

• What is my immediate impression?

• Can I describe the aroma without naming it?

• Does it feel familiar?

• Does a memory or place appear?

• Can I identify different aromatic notes?

• Can I distinguish it from the other two?

• Which one will I remember most clearly?

Then leave them.

Come back later and try again.

There is no score.

There is nothing to get right.

The purpose is simply to pay attention.

Reading the science carefully

Research into olfaction and cognition is developing, and there are some genuinely exciting findings.

But exciting research and established clinical evidence are not the same thing.

Studies vary considerably in their participants, methods, aromas, length of intervention and outcomes.

We should therefore be particularly cautious about claims involving dementia or the prevention of cognitive decline.

At present, this research gives us excellent reasons to remain curious.

It does not give complementary therapists permission to promise neurological outcomes that have not been established.

For me, that doesn't make the research less exciting.

It makes it more interesting.

Because there is still so much to discover.

Perhaps we have forgotten how to smell

Modern life asks a great deal of our eyes and ears.

Screens.

Messages.

Podcasts.

Television.

Traffic.

Notifications.

Our sense of smell rarely receives the same deliberate attention.

Yet it has been quietly accompanying us all along.

The smell of rain.

Fresh herbs crushed between our fingers.

Coffee.

A baby's head.

Someone's perfume.

The earth after gardening.

A familiar home.

More than twenty years ago, research into rosemary, lavender, cognition and mood helped open questions about aroma and the brain that researchers are still exploring today.

Neuroscience now allows us to ask those questions with increasingly sophisticated tools.

And perhaps the apothecary can play its own small part — not by making promises the science cannot yet support, but by encouraging us to become curious about this extraordinary and often neglected sense.

To smell deliberately.

To discriminate between aromas.

To make associations.

To remember.

To learn.

To notice.

That is why our Elixir journey begins here.

Not with an answer.

With a breath, an aroma and a question:

What do you notice?

Research behind this article

Moss, M., Cook, J., Wesnes, K. & Duckett, P. (2003). Aromas of rosemary and lavender essential oils differentially affect cognition and mood in healthy adults. International Journal of Neuroscience.

Woo, C.C. et al. (2023). Overnight olfactory enrichment using an odorant diffuser improves memory and modifies the uncinate fasciculus in older adults. Frontiers in Neuroscience.

Further systematic reviews of olfactory training and enrichment have explored possible relationships with olfactory function, cognition, brain structure and functional connectivity.

A note from The Living Apothecary

The research discussed here is emerging and should not be interpreted as evidence that essential oils prevent or treat dementia, cognitive decline or neurological disease.

The Living Apothecary uses scent as part of sensory exploration, education and wellbeing practice. It does not replace appropriate medical assessment or treatment.