Why You Can't Smell Your Own Cologne

There are many reasons why you might not be able to smell your cologne. It could be that your brain has become accustomed to the scent, a phenomenon known as nose blindness or olfactory adaptation. This occurs when your brain associates the cologne with your body odour and considers it harmless, causing the scent to become commonplace. Additionally, storing cologne in a hot, steamy bathroom can cause it to break down faster and change its composition. Age, diet, medication, and stress can also impact how a scent interacts with your skin chemistry.

Olfactory adaptation

When you are exposed to a scent for an extended period, your olfactory receptors become less sensitive, and your brain essentially learns to filter it out or ignore it. This is because the olfactory system is designed to detect changes, so if you're using a scent all the time, your brain will eventually decide that it doesn't need to pay attention to it anymore. This is similar to how people who live next to a highway stop noticing the noise after a while or how you may not notice the "smell" of your own house.

To combat olfactory adaptation, you can try "exercising" your sense of smell by actively thinking about the scents you encounter and creating connections between what you're smelling and remembering it for next time. This is similar to the detailed patterning that perfumers and chefs use to retain their keen sense of smell well into their 70s and 80s. You can also try increasing blood flow, as some scent molecules can be flushed out through the capillaries in the nose. This is why some perfumers run up and down a flight of stairs during their workday to keep their noses clear.

Nose blindness

Our senses provide our brains with a lot of information about our surroundings. Without a way to effectively filter through all this data, our brains could quickly become overstimulated. This is where natural adaptations like nose blindness come in. By decreasing the perception of scents that we're frequently or constantly exposed to, nose blindness can help prevent overstimulation of our senses.

When you inhale a scent molecule, it binds to a receptor on a special type of sensory nerve cell that detects scents. This nerve cell produces an electrical signal that reaches your brain, which then processes the scent. With repeated or continuous stimulation by a particular scent molecule, the nerve cell eventually stops sending its electrical signal to your brain, and you no longer perceive the scent.

Your brain blocks out non-threatening scents

Our brains are designed to filter out extraneous stimuli and focus on things that might be dangerous or important. Our brains prioritise changes in our environment, and we react to the sudden noise of a bottle being dropped or the smell of bleach over our own scent. We can test this theory by pinching our nose when eating vanilla or chocolate ice cream. Instead of tasting the flavour, all we can taste is sweet.

Our sense of smell is handled by the olfactory bulb, which sends information to other areas of the body's central command for further processing. Odours take a direct route to the limbic system, including the amygdala and the hippocampus, the regions related to emotion and memory. The olfactory signals quickly get to the limbic system, and smell and emotion are stored as one memory.

The olfactory system is described by relatively direct connections to brain structures involved in memory and emotion. The olfactory tract carries the axons leaving the olfactory bulb and projects to the structures collectively called the primary olfactory cortex. The piriform cortex is the largest of the olfactory areas and occupies a central position in the primary olfactory cortex. The other important cortical primary olfactory areas include the anterior cortical nucleus of the amygdala, the periamygdaloid cortex, and the entorhinal cortex. Olfactory information is transmitted from the primary olfactory cortex to other cortical and subcortical areas.

The sense of smell plays an important role in the physiological effects of mood, stress, and working capacity. Studies have shown that inhalation of aroma can highly affect brain function since fragrance compounds are able to cross the blood-brain barrier and interact with receptors in the central nervous system.

The olfactory system contains a sensory organ (olfactory epithelium) and specific olfactory brain regions (olfactory bulb and higher olfactory cortex). The olfactory mucosa is the region located in the superior and posterior part of the nasal cavity, especially for the detection of fragrant molecules. It includes the olfactory epithelium and its underlying lamina propria. In general, the olfactory epithelium undergoes a continual process of neurogenesis in which new neurons are constantly generated throughout adult life, and this is the reason for discontinuity and spread of the olfactory mucosa.

The olfactory process begins when fragrances from the atmosphere enter the nose and attach to the cilia of receptor cells. In general, fragrance stimulation of olfactory receptor cells in the nose involves the interaction of fragrance molecules with olfactory-receptor proteins. The olfactory events undergo two different G-protein-coupled transduction mechanisms; one activates adenylyl cyclase to generate cyclic adenosine monophosphate, the other activates phospholipase C to produce inositol trisphosphate. Then they open channels admitting calcium, sodium and chlorine ions into the cell, leading to depolarization of the membrane and an action potential. Then the olfactory sensory neurons send the electrical signals to the brain via the olfactory bulb and higher olfactory cortex.

Your nose gets used to the scent

It's frustrating when you can't smell your cologne, especially when you've spent a lot of money on it. However, it's important to remember that your nose can get used to a scent, a phenomenon known as "nose blindness" or "olfactory adaptation". This occurs when your brain becomes accustomed to a particular smell and stops noticing it. In other words, your olfactory sensors drop their guard and become familiar with the smell because they no longer perceive it as a threat.

Olfactory adaptation is a vital phenomenon, according to Anne-Marie Mouly, a neuroscientist at the Lyon Neuroscience Research Center. It allows our olfactory sensors to quickly identify changes in our environment, such as scents that could be dangerous. For example, you may be able to detect the presence of a newborn baby in a house due to the smell of urine, but after a while, you get used to the smell and no longer notice it.

The process of smelling is straightforward: when you first smell a scent, the smell receptors in your nose transmit a signal to the limbic system of your brain. However, as you continue to smell the scent, your brain becomes used to it, and you gradually stop noticing it. This happens to everyone, even animals. Scientists don't know exactly why our brains adapt to scents so quickly, but it likely has something to do with how our brains process and prioritise sensory information.

So, if you can't smell your cologne, don't panic. Your fragrance is likely still good, and your nose isn't necessarily to blame. It's simply a case of olfactory adaptation. To remedy this, you can try taking a break from your cologne and switching to a different fragrance for a while. This will stimulate your nose and help reset your olfactory sensors. You can also experiment with different perfuming techniques, such as spraying above you instead of behind your ear. Additionally, training your sense of smell by exposing yourself to a variety of different scents can help combat olfactory adaptation and decline.

You need to train your nose

The human olfactory system is designed to detect changes. When you're exposed to a particular scent constantly, your brain gets used to it and eventually stops noticing the smell. This is called "nose blindness" or "olfactory adaptation". It is a vital phenomenon that allows our olfactory sensors to quickly identify any slight changes around us, especially scents that could be dangerous.

So, what can you do to combat nose blindness? The simple answer is to train your nose. Here are some tips to help you do that:

• Take a break from your usual cologne and change your fragrance. This will stimulate your nose, and your sensors will become more reactive.
• Experiment with different perfuming techniques. For example, a few drops of perfume above you will be perceived differently than a spray behind the ear or on an impregnated cloth.
• Try "nose-clearing techniques" to clear your nose of any residual smell. For example, smell coffee beans, a swatch of wool, or your un-fragranced forearm.
• Get your blood flowing. Some scent molecules will partition into the blood via the capillaries in your nose, so increasing blood flow can flush them out. Try running up and down a flight of stairs or doing an intense workout before applying your cologne.
• Exhale or swallow the mucus that moves through the olfactory region. This is gross but effective!

By following these tips, you can train your nose to become more sensitive to different smells and avoid nose blindness.

Frequently asked questions