The sense of smell
The olfactory sense, or the sense of smell is one of the five better known senses. The nose is the primary organ involved in the sense of smell. The nose, and its complex system and glands and epithelial tissues detect chemicals, usually in the air. Some receptors in the nose specifically detect pheromones.
Smell is a powerful sense, and is strongly linked to our emotions, and memory. We use it to detect danger, for example, from off or toxic food. It is also involved in sexual attraction.
Regulation of our senses is one aspect of our basic human needs.
Talking about smell
Talking about smell with toddlers and young children helps them to learn to communicate about the world around them. You can talk about what you think caused the smell, and whether it is pleasant or not.
Smell sensitivity and disorders
As with all senses everyone has a different level of sensitivity. This mean that some people can detect smells that most people cannot. They are known as hypersensitive. Other people, however, have lower levels of olfactory sensitivity and are known as hyposensitive.
There are a number of conditions that can change or impact our sense of smell. Covid-19 is well known for causing a loss of smell and taste, which is usually temporary. Growths in the nose or brain can also cause smell disorders, as can head injuries and some hormonal conditions.
Anosmia and hyposmia
Some conditions can result in a total (anosmia) or partial (hyposmia) loss of the sense of smell. It also is usually accompanied by a severely reduced sense of taste since much of the information that creates the flavours we experience when eating are in fact performed by the sense of smell. The two sense together are often known as the chemosensory system as both detect chemicals, and frequently work in partnership.
Parosmia is a condition that causes the smell perception of an odour to change significantly. For example, a smell that previously smelled pleasant now smells unbearable. This is not simply caused by a change in preferences, but by a change in the perception of the smell.
Phantosmia is when the body detects a smell that is not present.
Everyone also has a zone of regulation, a comfort zone for each sense. These are not always the same. For example, some days we may have a much bigger comfort zone and find strong odours cause us no issues, On the other hand, on on other days smells may be much less well tolerated. The following behaviours are exhibited by people trying to regulate their sense fo smell.
Behaviours relating to hypersensitivity include the following
- Avoiding people who eat strong foods, or wears perfume
- Telling people they smell
- Disliking, or reacting negatively to, smells which others do not notice, or do not mind.
- Choosing to breathe through their mouths rather than their nose
- Refusing to eat certain foods due to their odour
- Avoiding certain environments, or has to leave places (zoos, certain shops, food markets)
- Refusing to use public toilets
- Becoming distressed by household smells, even those which others find pleasant
- Basing friendships or person preferences on the way people smell.
People who are less able to perceive aromas may exhibit some of the following behaviours:
- Sniffing everything they come into contact with
- Not noticing noxious scents that others do
- Actively seeking strong odours
- Craving strong tasting food
- Complaining that food all tastes the same, or is boring
Using the sense of smell
Having fun with smell
There are a number of games you can play that involve the sense of smell, and activities you can adapt to add in additional extra smells.
You can scent homemade play dough or sensory dough, but be aware of how sensitive your child is. This may reduce their desire to play with it, if they find the smell overwhelming.
You can also play smell hunting: for example spray a sock with something strongly scented, like perfume, and hide it in the room. See how long it takes to find it using the sense of smell as your guide.
Try to work out what you can smell and where it comes from. Think of words to describe the scent.
Find out about how hound trailing and sniffer dogs work.
Scent can also be used for calming. Because the sense of smell is strongly linked to emotions and memory it can be a powerful sensory cue for calming. Using a certain scent at, or in the run up to, bedtime can associate it with relaxation and sleep. When this cue is conditioned the scent itself can make you feel relaxed and sleepy.
Lavender and camomile are popular choices. They can be used in a vaporiser, you may use a scented lotion or soap at this time, or some people chose to apply a scent to their pillow. Check that these do not cause any irritation first, especially if using with a young child.