The study authors fitted participants with wearable devices that tracked air flow in and out of their noses over 24 hours of normal activity. They followed 31 people with self-reported normal olfaction and 21 participants born without a sense of smell (known as “congenital anosmics”). They found that both smellers and non-smellers had similar breathing rates, but that, while awake, smellers’ respiratory patterns included an average of 240 additional inhalation peaks per hour, compared with non-smellers.

— Read more in People who can’t smell breathe differently at Popular Science.

But the new device Zhou and her team designed tells a different story. It detects the beginning of a sniff using changes in nasal pressure and then triggers the release of two odors, with one slightly farther from the nose than the other.

More than 200 participants were exposed to the sequences of two chemical odors in a single sniff. [...]

Test subjects were able to discern different sequences with above-chance accuracy, even when the odors were delivered only 60 milliseconds apart. The results suggest that our sense of smell has a speed similar to that of color perception.

— Read more in Your brain can perceive subtle odor changes in a single sniff at Science News.

Unlike the primary sensory brain areas that process sights and sounds, the one that decodes scents also responds to other stimuli, such as images and words associated with an odor, according to a study published today in Nature.

The extent to which neurons in the primary olfactory cortex, which includes the piriform cortex, respond to non-odor stimuli was surprising, says Marc Spehr, head of the Chemosensation Laboratory at RWTH Aachen University, who co-led the study. One neuron, for example, which activated in response to the scent of black licorice, also responded to the word “licorice,” images of the candy and the odor of anise seed, which is unrelated but has a similar scent.

— Read more in Double-duty neurons in primary olfactory cortex pick up on more than just scent at The Transmitter.

Our ability to detect odours – and how strong or pleasant we find them – also depends on how those detectors work in our own individual noses. We smell a fragrance like violets when a chemical called beta-ionone binds to a detector known as OR5A1. But for about half of people, that detector simply doesn't work. You'll never be able to smell beta-ionone if you're one of them, no matter how much of it is sitting in a vial in front of you.

— Read more in The great smell-off: TikTok sparks debate on American vs European noses at BBC.