Graham Lab Olfaction and cognition

Olfaction and cognition

Your sense of smell is connected to your memory

A decline in the sense of smell can be an early warning sign, often appearing years before motor or memory symptoms in neurodegenerative conditions. This includes Mild Cognitive Impairment, Alzheimer disease, Parkinson disease, and Huntington disease. Not everyone who loses their sense of smell will develop one of these conditions, but it can be a marker to suggest additional testing, such as cognitive testing.

Because the olfactory system has a direct, dedicated pathway to the brain’s critical emotion and memory centres, damage to this network may trigger depression and/or progressive cognitive deficits. Fortunately, research reveals that this system is modifiable through olfactory training (also called olfactory therapy), which can rebuild connections between brain cells and have an impact on brain region volumes.

Olfactory training is a structured, low-cost brain exercise programme designed to stimulate and repair neural pathways — a bit like a daily workout for your nose and your brain that stimulates the nervous system’s natural ability to repair itself.

See how the training works Read the research

The method

  • The method — Deliberately sniff a distinct sequence of strong, familiar scents twice daily.
  • The baseline scents — Using traditional, anti-inflammatory options including rose, lemon, clove, and eucalyptus.
  • The routine — Inhale each dedicated scent deeply for 10 to 20 seconds every morning and evening. Think about the smell and the memories it may bring up. By focusing deeply on these familiar smells, you physically stimulate the olfactory nerves in your nose, encouraging them to grow, rewire, and rebuild damaged pathways in the brain.
  • The timeline — Practising consistently for at least 4 months.
  • The outcomes — This simple, non-invasive exercise helps restore a faded sense of smell, sharpen memory and thinking skills, and lift depressive moods.

Watch the routine

This short video shows the training in practice — how to hold the bottle, how long to breathe in, and how to use each scent.

How to do olfactory training at home Download the video .

Start here

  • The training

    The four scents, the daily routine, and how long to keep going.

  • The science

    What the research shows about smell loss, training, and cognition.

  • About the lab

    Why Professor Graham studies olfaction and what the lab hopes to change.

  • Resources

    The pamphlet to download and print, and how to talk to your doctor.