When a person loses his sense of smell, does he also lose any memory associated with a smell?
—Ana Artega, via e-mail
David Smith, a professor of psychology and a researcher at the Center for Smell and Taste at the University of Florida, replies:
Normally people can detect a cacophony of odors using the 40 million olfactory receptor neurons that reside in the nasal cavity. When we encounter a new odor, these neurons send information about the whiff to a brain area called the olfactory cortex, leaving an imprint of the smell there. These memories accumulate over time to create a library of odors. Although we do not fully understand how the olfactory cortex encodes these memories, we do know that olfactory memories seem to be particularly rich—perhaps because the olfactory cortex is closely connected to the brain regions important for recollection. These areas include the amygdala, which processes emotions, and the hippocampus, which encodes and stores memories.
Damage to the olfactory receptor neurons because of a respiratory infection, a head injury or a neurodegenerative disease can disrupt the brain’s ability to process different smells. When olfactory neurons stop working altogether, a person develops anosmia, or the inability to discern odors. According to a 2008 report from the National Institutes of Health, 1 to 2 percent of the U.S. population younger than 65 years old, and more than half older than 65, have almost completely lost their sense of smell.
Smell (or olfactory) memory refers to the ability to recognize different odors in your environment. Some olfactory memories are unconscious—for instance, you may recognize a rose’s fragrance without remembering when you first encountered one. Other olfactory memories are conscious: they revive specific scenarios or emotions from the past. For instance, the musky smell of a friend’s apartment may remind you of your husband’s cologne.
Losing one’s sense of smell may not mean forgetting what things smell like. Even without the ability to detect odors in the environment, you may be able to imagine the nutty aroma of coffee brewing in the morning. And your memories associated with coffee may not be lost, either: you will probably still be able to recall the first time you tasted the bitter brew.
According to a 2008 study from the Journal of the Alzheimer’s Association, however, it is sometimes possible to lose the memories associated with smells. Neurodegenerative diseases such as Alzheimer’s and Parkinson’s can decrease a person’s sensitivity to certain smells as well as diminish the memories associated with these odors.
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7 Comments
Add CommentChemistry is the basis of life. Smells recognize chemistry, and likely preceded consciousness.
Reply | Report Abuse | Link to thisSmell is connected to taste. Last winter, I caught some kind of cold, and lost nearly all of both. It`s been 6 months, and it is still not right. Some sense has returned, but by no means all. Can`t smell rubbing alcohol, apparently skunk, etc. You have to be careful about cooking or eating.
Reply | Report Abuse | Link to thisI temporarily lost my sense of smell about 8 years ago due to a virus. As my ability to smell returned some things, mostly fruits, I perceived as having the smell I remembered. Other things like garlic, onions, and some unpleasant odors - like car exhaust - do not smell at all as I remeber them.
Reply | Report Abuse | Link to thisThat`s me all over. Eight years?! I guess that`s it for me, then. My friend and I got it at about the same time, similar results.
Reply | Report Abuse | Link to thisI lost most of my sense of smell due to a head injury 21 years ago
Reply | Report Abuse | Link to thisI occasionally pick up smells and immediately am aware of them
Cigarette smoke is one of them - very unpleasant
The smell is not as I remember it as some of the 'notes' must be missing
I'm aware of some fragrances - pleasant - but not all
Bill
Yes, like you Bill, I lost my sense of smell due to a head injury. What really frustrates me is when you mention it to another person, they most often comment 'how lucky you are'. Quite the contrary the loss of smell is as significant as the partial loss of hearing, sight, memory, perspective that goes with ABI. 18 years on and thanks to association I tend to look at a Rose and feel the texture. This compensates for the loss of smell and in my case the loss of the memory of the scent of a rose.
Reply | Report Abuse | Link to thisTraumatic event and hospitalisation did lead me to a scent I most definitely did not want. It brought me back to the first funeral home I had ever visited (aged 14) - it was my Uncle who had died and 18 years onward in the hospital, all I could smell was 'death odour'...that very specific smell. It was on the bedclothes, my body, everywhere. I am sure there is some reason in psychology for this association. I am also conscious that I may have body odour linked to not being able to smell....it is a bit obsessive at times but yes this relates to memory.
Food and the absence of smell is another issue. Recently diagnosed with anorexia, chronic fatigue, my humble suggestion is that the smell of home baking can be replaced by the importance of texture. I love smoothies, orange juice, and even a chocolate mouse. This is all about texture. Thankfully, my partner and carer ensures that I eat a proper diet but alas I no longer have stores in my brain cells what cabbage and bacon really smells like!
Michelle
This article contains a sentence that is patently false, and it is the topic sentence of a paragraph:
Reply | Report Abuse | Link to this"Smell (or olfactory) memory refers to the ability to recognize different odors in your environment."
This sentence is patently false, and besides that, it strays seriously from the question
"When a person loses his sense of smell, does he/she also lose any memory associated with a smell?"
The answer is that most of the time, one does not lose the memory of the smell. For example, if years ago, someone smelled a skunk and learned what it smells like - then completely lost one's sense of smell due to nasal disease - then one can usually still remember what a skunk smells like.
On the other hand, if someone lost his/her sense of smell due to brain disease or injury (stroke, tumor, infection, gunshot wound, etc.), then perhaps one would lose the memories of smells that one had experinced before. This is not a question that Dr. Smith addressed at all.
Dale A. Wood