Are there people with no sense of smell?
Also in this week's column:
- Why does natural selection take so long to get results?
- Why isn't pubic hair the same colour as hair on your head?
Are there people with no sense of smell?
Asked by Lucy Altmann of St Kilda, Victoria, Australia
People who cannot smell suffer from some form of nasal dysfunction.
- Anosmia is the complete loss of the sense of smell. Congential anosmia is rare, but can run in families. Traumatic anosmia can occur due to an injury, and viral anosmia can occur due to an infection.
- Hyposmia is the partial loss of the sense of smell.
- Parosmia is a distortion of the sense of smell. People with this dysfunction smell one smell and confuse it with another.
- Phantosmia is when smells are imagined.
- Presbyosmia is the decrease in the sense of smell due to aging.
D.S. lives in a major city in the southern US. He has submitted the following (which has been slightly edited):
To start from the beginning, I was born with congenital anosmia/parosmia, meaning that I have never been able to smell chemical odours (although vinegar and smoke do burn the inside of my nose, they do not have a "taste" outside of my tongue).
Despite this, my sense of taste seems abnormal, but not exactly hindered. I can usually detect up to around 10 distinct flavour combos in food, in addition to the mouthfeel, but as I've never had smells tied with taste, this is understandable.
I do, however, appear to have parosmia in the form of synesthesia [Synesthesia is a condition in which a stimulus, in addition to exciting the usual and normally located sensation, also gives rise to a subjective sensation of different character or localisation. For example, colour hearing. Synesthesia occurs often in artists and music composers].
While I can't smell a gas leak or fresh coffee, I can "smell" other things (a feeling like a taste coming from somewhere that my brain says is actually my nose). These sensations are predictable rather than random, and tend to indicate coincidences, corollaries, and shared points of reference across a domain, including déjà vu.
One of the best examples I can offer is that of books...if I read a book, wait a few weeks at least, then pick up the same text (be it a different copy of the same book, or a different version even), there is a smell as soon as I touch the cover, and it intensifies as I begin reading, becoming a very familiar sensory state, but very specific to that particular book. Each book has a different smell, not so much "good" or "bad" as distinctive, with the same text in a different physical book producing a uniform result.
This carries as well into my sense of touch, which is not only very acute, but also produces a sense like taste, if only in terms of a tactile/smell overlay that isn't really much like either one.
Given that background, it should be noted that I spent a good amount of effort finding ways to organise my memory as a kid, since I didn't have a pervasive catalogue of smells with which to link my memories together. I found out some interesting things while doing that, but the one I'm expressing here is that I seem to be ever-aware of my "zombie state" behaviours.
I am partly linked to my own heart rate...always aware of it and usually able to control it to whatever extent I choose. This is also true for breathing, achieving sleep, digestion, and a general knowledge of the state of most of my internal organs. I understand that this isn't the norm, but considering that I thought everyone was lying about smelling things until I was about 12, it didn't surprise me to have recently discovered that most people aren't even aware of their own heart beating (something else I just took for granted that everyone knew).
My eye-sight is nominal, probably not 20-20 any more, but I've never needed glasses. All the same, I'd classify my sense of sight as "complimentary". It's not secondary, I use it extensively, but it's on about the same level as my sense of touch and hearing. I do not usually focus my eyes on something to see it. I just pay attention in whatever direction is convenient, regardless of where my eyes are looking. They see just fine, but they tend to see everything at once, rather than one thing at a time... my brain does the focusing for me.
I am always at least somewhat consciously aware of all my activities. If I am driving, I am fully alert and do not tend to slip into autopilot. I never sleepwalk, and I almost always have a complete memory of events that wake me up, even briefly. I may not have reason to recall such memories without prompting, but will do so immediately if given a grain of information about the event.
My taste in food varies as widely as some people's mood swings. I can usually tell what kinds of things I need to eat given the condition of my body. Something I crave intensely one day might be repulsive for over a week until it is needed, at which point it will be delicious once again. These aren't whims that I consciously think up, but I am still fully aware of them, and they guide my eating habits.
This being said, there are still some things which I appear to enjoy regularly that give others pause...at best. Cooked beef tastes terrible, I can't stomach it, but raw beef is exquisite, almost orgasmic. Bone marrow, organ meat, seared animal skin, and cod liver oil are some of my favourites. Sushi and cooked fish are both essential, but I enjoy those about equally. Only chicken and pork I eat cooked, and pork rarely.
I am none-the-less a hardcore omnivore, and I love all fresh fruits and vegetables as much as meat. I drink my body weight in milk every month, and love fried cow-blood sandwiches. I've been checked for anaemia, but do not show any signs of it (nor any renal problems or parasites). I have a direct aversion to anything used for flavouring that isn't found en situ...things like coffee syrups, flavoured anything, aspartame, and fake-strawberry range in effect from disgust to outright animal panic. Diet Coke and fake strawberry, for example, taste so poisonous that I cannot usually swallow them (but crunchy beetles and ant eggs are just fine).
I grew up in a common middle-class home near [city and state deleted] USA, and my parents don't eat anything overtly weird. In terms of environment, I don't think I could reduce my stranger proclivities to anything specific.
I get very hungry whenever I see bison or yaks on TV, and I probably look a little creepy when I'm at the grocery store's meat counter. Given my persistent awareness of my own mortality, I am not usually aggressive or territorial, but this seems more a personal choice than anything. Despite this, I still don't get bent out of shape very often, and I'm wondering if this may be due to an inability to detect pheromones (which I'd considered earlier, given that my parents don't viscerally feel like my parents, even though I like them.
Stephen Juan, Ph.D. is an anthropologist at the University of Sydney. Email your Odd Body questions to firstname.lastname@example.org