Questions tagged [olfaction]

Olfaction is the sense of smell, which allows the perception of odors by chemoreception. It is a form of chemoreception. Olfaction has many purposes, such as the detection of hazards, pheromones, and food. It integrates with other senses to form the sense of flavor. Olfaction occurs when odorants bind to specific sites on olfactory receptors located in the nasal cavity (in mammals) or olfactory organs like antennae, maxillary palp etc (in insects).

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Are olfactive indicators always the result of inadequacy in sanitation?

Question If you can smell the scent of food in a thoroughly cleaned container, does that imply trace amounts of food particles remain? Scope It goes without saying that our sense of smell is ...
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Is there a scientific explanation for male and female fragrance preferences?

The following is only anecdotal evidence, but in my experience it's very consistent. When products have added fragrance (cosmetics, soap, air freshner, candles, etc), women often seem to enjoy the ...
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How can we smell odor direction if we breathe through one nostril at a time?

It's known that humans breathe mostly through one nostril at a time. How can we then perceive the direction the smell is coming from? Some articles claim similarity between olfactory and auditory ...
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How many “primary colors” can we smell? [duplicate]

There are many more that three visible wavelength in the visible EM spectrum, and yet we can model any color using only three primary RGB wavelength. Perception of an arbitrary color is equivalent of ...
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Can a memory trigger an reverse olfactory sensation?

The sense of smell is closely related to memory, which is why the smell can evoke even long-forgotten memories. But does the record of events, which is recalled in our memory, to the extent of an ...
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Is olfactory input processed by the thalamus?

Is olfactory input processed by the thalamus? I know olfaction is the only sense that can bypass the thalamus, but are there cases where the input can project to the thalamus?
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Why can we sniff so much?

What was the point for us humans (or other mammals) to develop such a strong sense of smell? Depending on the source, we can distingiush from 10.000 to even trillions of smells. But how was the ...
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Do human women smell different before they enter labour?

Surfing youtube I found a video where a cat shows a protective behaviour towards a pregnant woman soon to enter labour. In the miriad of average (dumb) comments I found another person stating that ...
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Is olfaction same among different individuals?

For instance if I smell the fragrance of a rose, well it smells like roses (little bit sweet). But is that smell the same for other people? Because we also have different voices, why not have ...
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Why do sulfur compounds smell?

Many of the compounds of sulfur have a strong odor. Hydrogen sulfide from rotten eggs, the mercaptans of a skunk, the odor compounds in onions and garlic, the bitter taste of brassicas (cabbage, ...
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Why does olfactory sensation need lateral inhibition?

Why does olfactory sensation need lateral inhibition? If it's not helping in spatial discrimination then why is it needed? Don't we just smell the odour which is more concentrated? My attempt: It is ...
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Why do cyanide and arsenic smell like almonds and garlic, respectively?

Why do humans smell arsenic as garlic or cyanide as almonds? Do both smells activate the same receptor? Is there any reason why our brain interprets these smells the same?
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Is there an RGB equivalent for smells?

Millions of colors in the visible spectrum can be generated by mixing red, green and blue - the RGB color system. Is there a basic set of smells that, when mixed, can yield all, or nearly all ...
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Is saturation of olfactory cells able to create a feeling of another odour when it stops?

I'm looking for at least one scientific study about how odours could impact human olfactory system and create some phenomenon that could be loosely compared to retina remanence. As an example, with ...
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Why do fishes have both a gustatory and an olfactory system?

I would like to know if there is a know reason for which fishes (and many aquatic species) have both an olfactory and a gustatory system. As far as I know, in all fish species the chemoreceptors, ...
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Are the destruction of Olfactory Receptor Neurons (ORNs) permanent?

I lost the ability to smell a particular smell due to an exposure to solvents years ago. It has never fully come back. I had always assumed that simply meant I had permanently destroyed my ORNs for ...
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When and why did humans start disliking the way we naturally smell? [closed]

Like many animals, humans produce a myriad of scents from sweating, bacteria, possibly pheromones, etc. Many of these scents are used throughout the animal kingdom for mate choice, recognition of ...
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Are there electron or proton receptors in our nose?

We can easily smell chlorine gas and its irritating odour, but we cannot smell oxygen gas. Do few protons and electrons make such difference to our olfactory receptors?
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How do our smell receptors detect and tell apart exhaust or cigarette smoke, or other man-made chemicals?

Somehow we can tell apart exhaust gas and cig smoke, yet neither of those would have existed when we evolved. How is it that we can sense chemical compounds that we've only synthesized recently?
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Does the human body metabolize what it smells, even in trace amounts?

I conjectured to a friend that some small amount of anything we smell is likely metabolized by the body. He disagreed. My thinking is that, if you are smelling something, some portion of molecules are ...
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How are smell and taste in fish differentiated?

The senses of taste and smell in different fish classes are described as two distinct senses; smell is mediated by the nasal openings, and taste by epithelial taste buds. They are both forms of ...
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What produces the strong odor of decaying dead animals?

Are there specific chemicals responsible for producing the strong, putrid odor that is present after an animal deceases? Also, how long does this odor last?
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Does our nose detect only if there is change in odor?

If I enter a room with certain odor, I can sense the odor. However, if I stay there for some time I cannot sense it anymore. A new entrant to the room can still smell it or I have to leave the room ...
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How to design an experiment with scent triggered memory recall in humans?

I've recently learned that scents can trigger memory recall in humans, and am thinking about setting up an experiment where I would attempt to induce memory recall through exposure to scents. In ...
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How many different smells can a human recognize?

How many different smells can a human recognize? If the space of smells is not discrete, how many dimensions it has (for example, the space of colors is three-dimensional).
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What is a “pure odorant”?

This article about testing for Alzheimer's, via changes in the ability to smell, said: She thought of peanut butter because, she said, it is a “pure odorant” that is only detected by the ...
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Will a garter snake eat unusual prey if made to smell like something normal?

I have noticed that my garter snake only eats after it has smelled it's prey to make sure it is a slug, and it doesn't matter whether it's moving or not. If I were to coat, say, a caterpillar with ...
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Are similar smells usually based on similar chemicals?

Building off of this question: Why does freshly cut grass smell like a watermelon?, is it usually the case that things that we perceive as having similar smells are, in fact, the same or a similar ...
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Why does freshly cut grass smell like a watermelon?

I found that, when I smell watermelon aroma outdoors, someone nearby has mowed the grass. Is there an underlying basis?
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Why dogs move their noses when smelling?

I read on Wikipedia that: The wet nose, or rhinarium, is essential for determining the direction of the air current containing the smell. Cold receptors in the skin are sensitive to the cooling of ...
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How is olfactory acuity rated/measured?

Acuity of one's sight is rated on the 20/20 scale. An online search appeared to indicate there is no comparable 'standard' to rate olfactory acuity. How is acuity of the olfactory system rated?