demonstrations:olfactory_adaptation
Olfactory Adaptation
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Senses and Perception
Alternative titles: Smell Adaptation
Summary
Olfactory adaptation is the process where the sense of smell becomes less sensitive to a persistent odor over time. This demonstration shows how quickly the nose adjusts when exposed to a continuous smell and how sensitivity returns when a new odor is introduced.
Procedure
- Choose a safe and distinct-smelling item (such as an orange peel, vanilla extract, or vinegar).
- Have participants smell the item for about 30–60 seconds, continuing to breathe normally.
- Ask them to describe how strong the smell seems at the beginning and after a short time.
- After adaptation occurs and the smell seems weaker or disappears, introduce a new odor (such as peppermint oil, coffee grounds, or cinnamon).
- Ask participants to note how quickly they can detect the new scent compared to the adapted one.
Links
Brain Waves - Smell (olfactory adaptation) activity - Parachute:
Sense of Smell Teaching Demo Plus Fun Activity - Teacher Cathy:
Variations
- Compare how long adaptation takes with different scents.
- Test whether stronger odors cause slower or faster adaptation.
- Alternate between strong and mild scents to see if adaptation differs.
- Try closing one nostril to see if adaptation occurs differently in each nostril.
Safety Precautions
- Only use safe, non-toxic household items or food-based scents.
- Avoid strong chemicals or allergens that could irritate the nose or cause allergic reactions.
- Do not place liquids directly in or too close to the nose; use soaked cotton balls or small open containers.
Questions to Consider
- Why does the smell seem to disappear after a while? (The olfactory receptors become less responsive to continuous stimulation, and the brain filters out constant signals.)
- Why can we smell a new odor so easily after adaptation? (The brain is primed to notice changes in the environment, especially new stimuli.)
- How might olfactory adaptation be useful in daily life? (It prevents the nervous system from being overwhelmed and allows focus on new, potentially important smells.)
- Why do some people describe this as being “nose blind”? (It is a common term for temporary loss of sensitivity to a familiar or constant odor.)