My friend, undergoing radiation therapy for cancer, had a distinct smell. As have those treated with specific chemotherapies.
Athletes smell. Indoor and outdoor athletes differently. Pool swimmers of chlorine, open-water swimmers of the sea.
Parkinsons and Alzheimers appear to have distinctive smells.
Diabetes is characterised for its distinct smell (and taste).
We are chemically-regulated, processing, producing, and (to an extent) signalling systems. The notion that there are associated perceptible scents is exceedingly probable.
Another aspect of older people (and again: Parkinsons and Alzheimers in particular) is a loss of the sense of smell. Which may mean that odors otherwise noticeable and addressed aren't.
I highly suspect you hit the nail on the head here from personal experience: My grandma no longer has any sense of smell (or taste, actually) at all. I recall at one point discovering a particularly pungent smell was caused actually by a cleaning solution, I think it was like an old can of Lysol that had no substance designed to improve it's scent, that of course, she wasn't aware smelled worse than death.
My biggest fear was things such as her potentially not noticing a natural gas leak, because the default indicator depends on a sense of smell. (I found out you can buy "explosive gas detectors", which are different than carbon monoxide detectors, if you want an audible alert for this.)
(How far gone? They are unable to distinguish, or detect, the sents of various Dr. Bronners soaps, directly before them.)
And mercaptan (the oderising component in municipal natural gas) is among the most detectable scents in existence. The reasons why it was introduced and its alternate uses are worthwhile reads. As I've noted elsewhere, virtually all safety regulations are written in blood, this one the 295+ souls claimed at New London.
T-butyl mercaptan (tert-butylthiol) is (CH_3)_3CSH.
I'm a shitty chemist.
The broader point was about smells, sensitivity, oderising alarms, and a bit of safety history.
The more so because the condition is quite often coincident with a tremendous state of denial. Anosognosia:
https://opinionator.blogs.nytimes.com/2010/06/20/the-anosogn... (part 1 of a 5-part series)
More interesting are cases where the lifestyle causes smellable long-term changes to body chemistry that can't be cleaned off.
If you do it often (e.g. swim professionally), why not?
But these things are not easy to research as reliable VOC detection requires lab setup (GC-MS)
Technically, althlete odors generally are foreign substances / interactions, at least in part.
(Not sure if you spoil the barrel or not though.)
I could tell a friend had just left their home from the odor when they lived at a particular place¹, and sometimes, I can tell if some item of clothing has been left at some place (not that I'm special at that).
The odor the author of the article could smell at her place after renting it for a month could have been a (mix of) perfume(s) their guests used.
Obviously, people have their own odor on top of (or under, more accurately?) that.
¹ in a forest -- no, I'm joking.
I have mild synesthesia myself - I hear flavors. I can say "I hear flavors", but that doesn't help to tell you what different flavors sound like, because sounds themselves are very hard to describe in words.
The best way to experience something like synesthesia is under the influence of LSD or similar drugs. Not that I recommend it, but it does work. "When colors taste like music" is my favorite description ever.
I asked this question in my previous comment because I've read about people having synesthesia discovering quite late that no, to most people, smells or figures don't have any specific color or character (depending on the involved senses), during a conversation in which they take for granted that their interlocutor experiences it too.
My father himself kind of realized that contrary to many people, he sees months of the year as a ring, when I spoke about synesthesia, and said that some people having synesthesia may see numbers or years in a specific shape, that does not change across their whole life (and, indeed, he confirmed this point about him).
So I wouldn't say I'm synesthetic, but at the same time I can't really point to a clear difference between how my mind associates numbers with locations in a spatial structure, and how my wife's mind associates them with colours.
I also can't really say how those associations are different from the kinds of associations that the mind seems to make to anchor new experiences and information into memory. I'm not explaining that very well, but overall I half think synesthesia seems more like just an atypical manifestation of a probably universal human trait, and less like a rare oddity.
These representations are the same since as far as I can remember. I know that some people I discussed with don't think they have such a representation for numbers or dates. It seems to correspond to the description given in .
I think it may have an impact on my memory, at least for dates (but nothing extraordinary). It's usually easy to remember meetings and events in the year, because they somewhat appear in the representation, I don't really need a calendar if there are not too much things scheduled (but I note in a log, just in case, and it's not completely reliable too).
You might have calendar synesthesia [2,3], and maybe me too, but maybe weaker than yours or my father's.
And yeah, it's not something we really see, its a representation that automatically comes into the mind without us trying to at all. Right?
Maybe many people actually have some form of synesthesia.
Translation of :
> Like “numerical synesthesia”, spatio-temporal synesthesia is a mental map of the days of the week and/or months of the year. People having this kind of synesthesia state that they can “see the time” as a ribbon, a ring or a circle for instance. According to some studies, these people would have particular synaptic connections in their brain, allowing them to live time like a spatial construction.
> Like all the forms of synesthesia, “spatio-temporal” also shows a permanent feature: tested months later, someone having synesthesia will report the same experiences they had previously reported.
The Wikipedia article points out that in theory, all logical synesthetic combinations are possible. I suspect that if you tested broadly for any kind of synesthetic experiences, you'd find a significant portion of the population had them, maybe even the majority.
Same for me.
> In article 2, the researchers are said to have asked their subject to recite every third month going backwards, apparently to test that it's not just a mind's eye visualization
I would be terrible at this task. I don't see the whole year (week) at once. This representation would not be of any help for that. It's here when I am scheduling / planning, or when someone is saying / I'm reading a date.
Sounds that trigger migraines are mostly certain kinds of echoes - the kind from sharp sounds in large, hard rooms like gymnasiums. I can't really be in a gym with people applauding.
Also, are there any particularly noteworthy smells in terms of representation?
I have to admit, the idea of a visual artifact for smells is amazing!
noteworthy? If I concentrate I can follow the trail of someone with a strong sent that had walked by in the last say 10 minutes like a blood hound. I _know_ when fish is labeled incorrectly when I do my weekly grocery shopping. I know when that person from work says they are quitting smoking, but have had a smoke and are lying. Just walking around outside, the amount of death from animals would surprise you.
Very specifically on the visually side I come across a food item that looks slightly different. No one else notices this change in smell but it is a fun game realizing that maybe the recipe changed ever so slightly or something.
Mostly I learned long ago to not talk about it in person because then people get very curious and then get extremely self conscious.
I'm a super taster for a few things and I suspect that whatever odor that is, I can detect it better than most. Anyway, thanks for your description!
So to be more exact you can "see" smells with your mind's eye but you do not actually see anything with your physical eyes when smelling something.
More when I smell the grass I "see" in my mind what that smell looks like (purplish).
 Another one is the upcoming adaptation of The Colour Out of Space
A few years ago, I was astonished when I realized that I could smell that exact same smell again. Only this time, to my horror, I discovered that I was now the source of that exact same precise smell. Only I don’t smoke, and my labor is mostly mental.
It’s not a knock-you-over-with-body-odor smell. You can cover it with deodorant or other perfumery type of application. But it is the baseline smell, minus all additional covering odors.
I finally decided that it must be a combination of genes and aging, since I am now close to the age when I recall that my grandfather smelled like this.
Now he gets anxious when he smells old people. So from my anecdotal evidence, I think they probably have a distinct smell.
My theory is that the smell is distinct because of pharmaceuticals. A lot of older people are on all sorts of medications. I think a lot of medicines cause the body to give off differing odors. From personal experience, I've noticed my body odor change when on different medicines. And have actually noticed that other elderly people I've been around have a faint chemical odor to them.
(Those two studies had different conclusions. The third study defined "old" as 75 and older, but found the most intense and unpleasant orders in middle-ages males, 45-55, so again, frailty doesn't seem likely to be a significant factor in terms of a strong or bad old smell.)
Edit: also, I kinda doubt your assertion about the bathing habits of older people. I wonder what you base that on?
How does she smell?