Have you seen the ads for the air freshener Febreze? The ads suggest that we are “nose blind” to some of the smells in our own homes. That is, we don’t notice any ordinary smells in our homes, but other people do. Have you ever been away on vacation then come home and noticed a scent in your home you didn’t notice before? I have, so I wondered if the Febreze ads were correct and that nose blindness is a real phenomenon, and apparently it is.
Pamela Dalton has been studying nose blindness for more than 20 years. She is a cognitive psychologist with the Monell Chemical Senses Center and she has an explanation for why we go nose blind.
According to Dalton, when you introduce a new scent into your home, your odor receptors pick up the new odorant molecules and send the information to your brain’s olfactory bulb which is part of the limbic system. If the scent is understood by the brain to not be dangerous, such as a pleasant scent as opposed to a “dangerous” scent such as a fire or rotting meat, then the nose receptors shut off. When the nose receptors shut off, the scent becomes less intense. The theory about this is that the scent is not dangerous so the brain does not need to pay attention to it. After a while you become less and less aware of the non-dangerous scents in your own home. The theory continues that this would allow you to more easily pick up on a dangerous scent if you needed to, like a bleach spill, a toaster fire, or rotting food.
Dalton explains that hearing is the closest sense we have to smell that mimics how we can go nose blind. For example, those that live near a train track will eventually become accustomed to the sound of the train and not notice it anymore. That is because the brain perceives the sound as not being a threat. This is known as sensory adaptation and part of how humans adapted to their environments for survival.
There are ways to overcome nose blindness. One is to exercise vigorously. This increases blood flow and helps the nose pick up on familiar smells once again. Another way is to worry more about smells. This fear regarding a smell will interfere with the sensory adaptation of smell.
So if you want to know what your house, apartment or dorm room really smells like, you can: go away for a week, go do some exercise, or start to worry about the smell. When you finally figure out what your living area actually smells like to everyone else, and if it is disagreeable, you can succumb to the marketing of Febreze. How genius to market their product in such a new way! It’s not so your environment smells better for you and your family, it’s to save you and your family from the embarrassment of having a smelly home!