Memories Triggered by Smells

January 18, 2007 10:02 AM

For a lot of people, a particular aroma can be a strong trigger for memory. I don't think it works in reverse: why is this?

If I get even the faintest whisps of aroma from a certain musk joss stick [incense], I am immediately transported back to the streets of Bangalore and Hyderabad which I visited many years ago. This can be as mild as a passing thought of 'India' in general or if I stop and concentrate, it can be vivid remembered scenes and colours and peoples' faces - you know, strongly evocative.

But in the absence of some aroma trigger, if I think about India (and I just use this as an example), even if I concentrate to try and remember events or people or places, I may get passing 'visions' or thought rememberances perhaps, but they never involve actually experiencing the same smells. In other words, smells don't seem to be able to be evoked but are themselves strongly evocative.

Is this just me? Do some people experience aromas when they think about specific people/places from their past? Are there all different grades of aroma-memory-responses? What's the interplay going on here? Is the sense of smell different in this respect to our other senses? Why? And I guess, arising from this, why can the smells make me remember things more vividly than my non-aroma mediated powers of concentration?

posted by peacay to science & nature (17 answers total)

"Olfaction is the sensory modality that is physically closest to the limbic system, of which the hippocampus and amygdala are a part, and which is responsible for emotions and memory. Indeed this may be why odor-evoked memories are unusually emotionally potent." Also interesting.
posted by DevilsAdvocate at 10:14 AM on January 18, 2007

I had the reverse experience yesterday -- while thinking about my middle school Shop teacher, I could "smell" (in my mind) the branded wood and soldered metal I always associated with his classroom. The added sense memory made the memories much more vivid and powerful (good memories, btw), just like when I smell a real aroma and it triggers a memory. Writing this now though, the smell is not coming back to me the way it did yesterday. I guess I have to be pretty deeply immersed in a memory to remember aromas, so it doesn't happen often.
posted by junkbox at 10:15 AM on January 18, 2007

Aromas are very hard to describe. So I think that very fact makes it hard to remember them, especially in the easy way we remember what things looked like.
posted by zpousman at 10:31 AM on January 18, 2007

Like junkbox, I go the other way sometimes. It's not too frequent, and it's usually people more than places or events... can be kind of a weird experience.
posted by rkent at 10:33 AM on January 18, 2007

For the same reason the keys on your keyboard don't start moving when you bring up a saved Word document. Yet when you type something and save it, you see similar documents in that location. Smell is a physical process involving molecules locking on to senors. That experience then is stored in the brain along with other experiences associated with that odor, jogging them in the process. Memory has no way of triggering that physical process, unless you're a synesthete.
posted by weapons-grade pandemonium at 10:50 AM on January 18, 2007

I go both ways. I believe I have a very good "smell memory" especially with food. Could be because I am around it all day, but I am quite capable at determining "what's cookin" by smell alone.
posted by sindas at 10:51 AM on January 18, 2007

I'm like junkbox quite often, almost like it's a reverse synaesthesia. Many times I'll hear a song from my past and be able to smell my life at that point, my parent's house, dorm room, old girlfriends, etc.
posted by rhizome at 10:59 AM on January 18, 2007

Is this just me?

No.

Do some people experience aromas when they think about specific people/places from their past?

Yes.

I get this most powerfully when a girl walks by wearing a perfume that an old girlfriend once wore. Its a very strong experience - I can see old memories quite clearly that I normally wouldn't be able to access by just trying to.

Never experienced it the other way, but I damn well wish I could learn how to.
posted by allkindsoftime at 11:18 AM on January 18, 2007

I generally work one way. The one exception was a year or two ago. I woke up in bed, thinking my father (long dead) was in the room, and I could smell the booze, cigarettes, musk and gas of his scent. It was incredibly vivid.
posted by Good Brain at 11:33 AM on January 18, 2007

I don't have a lot of memories for which I retain a memory of the smells, but I do have some. Especially of the beach; I can remember the smells of the beach and experience them at least as well as remembered sights and sounds.
posted by solotoro at 12:12 PM on January 18, 2007

Like most, I have had very vivid memories triggered by certain smells that were present when the memory was made. The experience of the smell automatically, uncontrollably brings the memory to mind.

On the other hand, I can't think of any times when a certain memory of an experience triggered a corresponding memory of the smell. I can definitely recreate the smell in my memory if I think about it, but the visual/emotional memory doesn't cause the smell memory to come automatically flooding back.

However, I think the true opposite of "smelling something in the present triggers a memory of the past" would be "experiencing something in the present triggers the memory of a smell" - and I think if you're going through an experience that was previously associated with a smell, then that smell is probably already present in your current surroundings.

For example, the smell of sawdust immediately brings to mind memories of my dad's workshop from when I was a kid. However, being in a scent-free workshop probably wouldn't immediately make me remember the scent of sawdust. But in reality, it's unlikely that I'd be in a workshop that didn't already smell like sawdust - so there's no chance for the current experience to trigger a scent memory.
posted by vytae at 12:42 PM on January 18, 2007

I, too, remember smells when I think about some things. Generally these are strong or important smells, but sometimes memories just have a smell associated with them (this seems to be especially true of places).
posted by fidelity at 12:51 PM on January 18, 2007

Olfactory cortex, the part of the brain responsible for smells, and the hippocampal formation, which is the part of the brain that consolidates memories, are both evolutionarily quite old. They are simpler in structure than the complicated association cortex that makes up language, visual, and motor areas.

Olfaction and memory areas in the brain, then, are not only physically close but also structurally and evolutionarily similar. It also happens that they're quite well connected to each other.

Neuroscientists point to these reasons as partial explanations for the phenomenon you observed, which is well-known. Here's a good article that talks a little more about it.
posted by ikkyu2 at 1:20 PM on January 18, 2007

When I think of the San Francisco Zoo, I immediately "smell" the eucalyptus trees dripping with fog. I haven't been to the zoo since grade school.
posted by oneirodynia at 8:34 PM on January 18, 2007

fwiw, I would think associating past activities with their odors would have a particularly strong survival value, evolutionarily speaking.

the other way, not so much, which would be one answer to the "why?" part of the question.
posted by Heywood Mogroot at 10:49 PM on January 18, 2007

Works backwards for me too. My grandfather's music room in a house they used to live in ages ago (and lived there for ages) always smelled like Old Spice, and if I think about being in that room for very long I distinctly begin to faintly smell Old Spice.
posted by Quarter Pincher at 12:56 AM on January 19, 2007

I can smell Christmas if I think about it.
posted by jitterbug perfume at 9:50 PM on February 14, 2007