Learning smells: the science

    Learning smells: the science

    post #1 of 62
    Thread Starter 

    Picking up from this thread:

    http://www.basenotes.net/t/373278/plz-help

     

    Regarding my quest(ion) on the science behind how one (a perfumer to be?) learns, memorizes, recognizes and recalls smells. Your input is welcome :)

     

    Here is the latest from DrSmellthis:

     

    Quote:
    Originally Posted by DrSmellThis View Post

    No abrasion whatsoever taken fom your post. Was just trying to characterize information and it came out wrong.

     

    I believe perception in the general population is significantly synaesthetic, and that article and its references aren't a bad intro to that. It gives several examples where the different perceptual areas of the brain work together, and reviews cases where someone loses a sense like hearing and brain perception adjusts to compensate with dynamics between different areas of perception, in addition to the example from the previous post. It dovetails with issues of brain plasticity, the ability of our brains to grow, change and adapt.

     

    I don't think it's an accident that people describe smells in terms of other senses, and I would wager you could see it on funtional brain imaging. For example, while smelling and describing one's favorite smells; one should detect some activity in, say, visual or auditory regions, and so on.

     

    Some of the research has been done, some hasn't, like with anything. But I believe "structures of perception" flowing via perceptual areas of the brain and their interaction, are shared between senses.

     

    Subjectively, it is also common for smells to trigger rich memories involving multiple kinds of sensory information. That is because the smell was not just stored as a discrete smell in the first place, but as a narrative memory, a part of a life story, with all the elements stories contain.

     

    So smelling something is rarely an experience of simply processing odor chemicals as new, discrete and isolated stimuli, which we process as a mere collection of raw olfactory properties. But rather the smell perception itself is at once laden with meaningful associations.

     

    So essentally, one would need to use terms of "metaphor" (expressing something in terms of something else, put one way) to accurately characterize our original neurology, perception, and experience.

     

    In the past metaphor has been regarded as a kind of "lie", like myth; whereas in a sense it is starting to look like the most accurate way to characterize the world, by grounding everything in the original experience which involves multi-sensory, associative neurology.

     

    There are any number of interesting potential implications of that, for me, involving philosophy of science and perception; education; and society. For example, it would suggest the fundamental importance of art; and a proper role of artists, to bring people in touch with their their own realities/experience, since art is the medium of metaphor. It would also suggest the value of educating young people in the arts; especially for the purposes of general brain development, consistent with other research on that topic.

     

    The study of smell is full of potential insights about various areas of life (e.g., human sexuality), which is one thing that makes it fun.

     

    post #2 of 62
    Thread Starter 

    My questions are:

     

    In order of 

    1. there is a smell: sensation occurs

     

    2. there are neuro-psychological & - physiological systems at work (the brain assesses, analyzes and stores this information)

     

    3. there are reactions: unconscious (physiological) and conscious (psychological and cognitive, this includes language: responding to a smell with words and associations) 

     

    4. there are actions: physical (for example recoil if the smell is foul) and psychological (like, don't like, danger, reminds me of .... memory)

     

    Each of the above can result in a series of questions, some interest me, some don't. Here are the questions that I like to research:

     

    2. Which brain pathways are activated by a smell sensation?

    Where in the brain are smell sensations being stored? Are they even stored as such or are they linked to other pieces of information right away? 

    Why most people cannot recall a smell? (think lavender, a person can recall a picture of the plant or lavender fields or an object that smells like lavender but not the sensation itself)

     

    3. Can the various reactions help towards speeding the learning process of a smell sensation, specifically recognition? Can that result in a universal language/vocabulary of smell?

     

    Interesting research, articles and books, please feel free to make suggestions:

     

    Odor Sensation and Memory by Trygg Engen (1991)

     

    Perfumers' expertise induces structural reorganization in olfactory brain regions 2012

     

    The Effect of Verbal Context on Olfactory Perception Herz, Rachel S. 2003

     

    Odor Identification, Consistency of Label Use, Olfactory Threshold and their Relationships to Odor Memory over the Human Lifespan Johann P. Lehrner

    Olfactory perceptual learning: the critical role of memory in odor discrimination  Donald A Wilson, Richard J Stevenson 2003

    •  
    post #3 of 62

    Difficult questions Irina, and ones which very few will be able to answer; I don't think I can.   I have no idea where smell memories are stored nor down which pathways smell sensations travel.   There has been much research done on the part of smelling that occurs in the nose (indeed I think a Nobel Prize was awarded for such research) and there has been the ongoing debate between the likes of Luca Turin, with his theory, and the more traditional ides.   However, as far as I am aware very little has been done to find out how the sensations of smell are processed by the brain.   All I know is that the sense of smell is a very ancient one and I would guess that the more primitive part of the brain (that part shared by more primitive, older species) would be involved; the Amygdala for example.   A new born baby, whilst it cannot hear or see very well, can smell and is attracted to its mother by smell.

     

    You say that most people cannot recall a smell; you maybe right, but with practice it is possible to do this.   You mention Lavender, as I type the word I can smell it.   I have developed an Odour Memory. one of the most important qualities of a Perfumer.  And whilst it may be difficult to recall a smell simply by naming it, the opposite is a very common experience.   If you were to smell something that you first smelled many years ago, I think you would be able to recall where and when you first smelled it.

     

    I doubt if there could develop a universal language of smell; it is too subjective and too cultural.   We react differently to the same smell depending on all sorts of factors; our state of health for example, if we are hungry, or not, even the time of the month (if female).   I think that there are many neurological processes at work in our ability to interpret smells.

     

    I'm guessing that the advances in the techniques of brain scanning will reveal much, and may even start answering your questions.   It is a fascinating topic.   

    post #4 of 62
    Thread Starter 

    Damn my reply vanished...

     

    Anyways, thank you, David for your input!

     

    I totally agree that it is a fascinating topic and there is still so much we don't know (hence my trepidation to do some research).

     

    I also agree with you that most people can recognize a smell that have smelled before, that is 1 recall mechanism. The other recall mechanism I was referring to is the one that for example works with visual and auditive stimuli in most people (for example memorizing and then reproducing written words, pictures or sounds) but with smell most people can't actually experience the olfactory sensation of lavender when only presented with the word lavender or a picture of a lavender bush. But the puzzling thing is that indeed, like you say, with training that IS possible. Meaning perfumers brains are differently wired, which has been confirmed by latest research see article above from 2012. Meaning just like people that learn to read sheet music can actually hear the music, people could smell certain smells by only being presented with certain words of smelly stuff. (Or hearing a certain tone, like Luca Turin's work implies). There is some synaesthesia at work here.

     

    Meaning one can (theoretically) work out how common people can learn to smell something by offering information/stimuli that is not olfactory. Like inventing sheet music for the nose smiley.gif


    Edited by Irina - 6/17/13 at 3:37am
    post #5 of 62
    Why most people cannot recall a smell? (think lavender, a person can recall a picture of the plant or lavender fields or an object that smells like lavender but not the sensation itself) this is wrong- people recall smell the same way as pictures, there is the same brain activity as when recalling picture.
    post #6 of 62
    no practice is needed to smell, like no practice is needed to hear, or see......nor my nose will ever work better with practice :) haha i just can get better understanding....of what i smell
    post #7 of 62
    Quote:
    Originally Posted by David Ruskin View Post

    ; All I know is that the sense of smell is a very ancient one and I would guess that the more primitive part of the brain (that part shared by more primitive, older species) would be involved; the Amygdala for example.   A new born baby, whilst it cannot hear or see very well, can smell and is attracted to its mother by smell.

     

     

    I'm guessing that the advances in the techniques of brain scanning will reveal much, and may even start answering your questions.   It is a fascinating topic.   

     

    yes how new technology is available it is known fact now that when one recalls smell there is the same brain activity going on .. also there is a bit of a myth how sense of smell is more primitive, it is very important and that is supported by the fact that Olfactory Receptores gene family is the biggest in the human genome—testimony to the evolutionary importance of odor perception, i think its 1500 varieties but by no means it says that sense of smell is more emotional for that matter!....or has anything to do with emotions..or better memory etc.. science still doesnt know why is smell this important , does it have to do with sexual hormonse, or with food.....or whatever....by that mean we humans are not worse then dogs!....i.e. dogs can not smell this much better then we can .....as is general perception
    post #8 of 62

    I am left-hander newbie. Interesting, how many left-handers are here, between of such deep smells analysing topics authors, between perfume creators? I don't want to say that left or right handers are better, or what some can smell better. But this can be one of possibilities, why some people have a better, wider sense of smell. For smells, left nostril are more important: http://171.67.121.218/content/118/2/183.abstract
    One of facts, that "connections between the right and left sides of the brain are faster in left-handed people. This means information is transferred faster, making left-handers more efficient in dealing with multiple stimuli and using both sides of the brain more easily". What do you think about this?

     

    post #9 of 62

    I know at least two Perfumers who are left handed; which means that I know many, many more who aren't.

     

    No iivanita, most people have great difficulty in recalling a smell.   One's sense of smell can be improved by practice.   I do not know if it is the same brain activity when we smell something, when we try to recall a smell, when we see something or when we try to remember an object; but I very much doubt it. 

    post #10 of 62

    Happy to see the replies and interest.

     

    David is correct. Perfumers and those who practice, I believe, develop quite a bit neurologically, in the form of smell memory.

     

    Not only can I recall individual scents, imagining them vividly (I also smelled lavender immediately upon it being mentioned above), I can smell combinations of smells in my mind. Even if I've never smelled that combination in person: Even though I can't recall ever mixing black pepper with Tonka (just those two alone), I vividly smelled their combination in my mind the other day. Vividly. Then I realized how many perfumes have that accord. I sincerely don't need to actually smell them together, because of how vivid it was. I know David can do this too without even asking him, so can Chris, pk, and others here as well.

     

    With music, it's the same thing. Devoted musicians develop a huge amount of memory available for remembering tones and tunes, for controlling each finger on their hands independently, for hearing and analyzing, etc., etc.

     

    Why is smell memory a relative weakness compared to other senses, typically, for humans?

     

    The most obvious reason is that, despite the huge evolutionary and genetic prominence of smell for mammals (including humans), most people do not use their senses of smell, and that part of the brain atrophies and/or doesn't develop fully.

     

    That is because we have separated ourselves from nature, and because we don't need our sense of smell to survive very much when we spend all our time living indoors. Therefore we cannot remember smells very well, as we do not have the available memory, to use the computer analogy. With practice we do develop that neurology, though.

     

    But the amount of olfactory stimulation you get from a long hike in nature -- all the "olfactory stories" nature tells you, dwarfs the very limited and relatively empty smell experience we get indoors.

     

    Regarding canines. Dogs do have better smell in the sense of absolute threshholds for detecting smell. However, humans are overall equally adept at smelling as dogs -- potentially, due to the fact that most of smell is not about detection threshholds, but about the analysis of the information, which humans excel at, potentially.

     

    Interestingly, psychiatry and psychology has long regarded "olfactory hallucinations" as a symptom of schizophrenia. I guess it can be. However, I have "olfactory hallucinations" -- simply imagining smells vividly -- all the time, as David and I bet other perfumers here do also. I don't believe I could do that before taking up an interest.

     

    Incidentally, I'm left handed, and do believe lefties often have a leg up with creativity. However, much of perfuming is chemistry, and so there is just as much reason for both right or left brained people to be involved and skilled, not that it's an either-or proposition. (The corpus callosum, or the neural network that connects the two halves of the brain, can also be developed, btw.)

     

    Too many interesting comments and questions here to discuss in one post.


    Edited by DrSmellThis - 6/17/13 at 12:38pm
    post #11 of 62
    Thread Starter 
    DrSmellthis if you ever find some time to refer to some specific research regarding the very interesting points you make, I would love to read more. Especially on specific olfactory brain training and brain activity when virtually smelling. Many thanks in advance!

    P.s I'm right handed and so are many other perfumers I know. Thank you for the article, Ramute!
    post #12 of 62
    Quote:
    Originally Posted by David Ruskin View Post

    I know at least two Perfumers who are left handed; which means that I know many, many more who aren't.

    No iivanita, most people have great difficulty in recalling a smell.   One's sense of smell can be improved by practice.   I do not know if it is the same brain activity when we smell something, when we try to recall a smell, when we see something or when we try to remember an object; but I very much doubt it. 

    With all therespect what do you base your claims on? you are not brain scientist? I read this from 2 scientists....it is very usual thing for everyone.: people can recall smell!!......even logical, i wonder who invented that nonsense first place!!?
    Edited by iivanita - 6/17/13 at 3:13pm
    post #13 of 62




Loving perfume on the Internet since 2000