Individuals with a loss of smell, anosmia, have a reduced quality of life. French national research scientist, Halina Stanley, describes people with long-term anosmia are at higher risk of mental health disorders. Research conducted in 2018 discovered that electrodes placed in the sinuses near the olfactory bulb, the brain region that processes odor signals, could stimulate perception of smell. Scientists are now attempting to develop implants that could more directly and specifically stimulate the olfactory bulb, a device similar to cochlear implants. Although, such technology would be complex and invasive.
The trigeminal nerve receives signals from all over the face including the nasal cavity, which aids in detection of the temperature of inhaled air and the presence of irritants. Certain chemicals from food trigger trigeminal nerve endings. To recruit this sense scientists designed a system with a chemical sensor to detect certain odors and encode each as a distinctive pattern of electrical signals, similar to a nasal Morse code. Those electrical signals are then delivered via electrodes clipped onto the nose's inner wall. Participants with olfactory disorders and normal smell were hooked up to the device to determine if they could detect electrical signals sent into their nostrils. All participants described the stimulations as slightly unpleasant and irritating.
The scientists also tested whether people could discriminate between different smells using the setup. They held scented stick close to the opening of the odor sensor to be encoded into an electrical signal. Some participants could differentiate among stimulations for different odors but could not say what the corresponding smells were. Others struggled with the task. The technology isn't going to capture the overall experience of smell but it will give the user the ability to detect odors. What is your take on the device? Would you use it if you lose your sense of smell or would you rather be without the sense?
References:
Artificial ‘nose’ tells people when certain smells are present. (n.d.). Retrieved November 30, 2025, from https://www.science.org/content/article/artificial-nose-tells-people-when-certain-smells-are-present
I remember doing a silly little experiment as a kid where you plugged your nose and tried to tell what flavor of skittle you ate with your eyes closed. I remember getting all of them wrong and realizing that without my sense of smell I wouldn't be able to enjoy the simple things from before. It is very interesting to see how people are trying to improve and help those with a lower sense of smell because it seems like a hard issue to truly "cure."
ReplyDeleteHi Alex!
ReplyDeleteAn artificial nose got me thinking, why is that certain people have naturally stronger senses of smell than others? And I wonder if nose shape plays a role in perception. And if that leads them to an advantage or disadvantage when it comes to diseases that can impact smell such as COVID-19. There is a genetic component, mutations in our olfactory genes have turned majority of our olfactory genes into “pseudo genes” (Gross, 2007). COVID-19 is the first time I believe that I heard of anosmia—but there is such a thing as specific anosmia. About 1 in 10 individuals reportedly cannot smell hydrogen cyanide (poisonous gas) and 1 in 1,000 cannot smell butyl mercaptan (skunk smell!) (Gross, 2007). I wonder if this artificial nose will be able to identify these genetic changes within the patient.
Gross L. (2007). A genetic basis for hypersensitivity to "sweaty" odors in humans. PLoS biology, 5(11), e298. https://doi.org/10.1371/journal.pbio.0050298
Your post highlights a really clever workaround using the trigeminal nerve to restore basic odor detection when normal smell pathways fail. Even if it doesn’t recreate true smell, the safety benefits alone would make it worth using for many people.
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