Neuroscience
Show one image exclusively to one eye and a different image exclusively to the other eye and rather than experiencing a merging of the images, an observer's percept will flit backwards and forwards randomly and endlessly between the two. This "binocular rivalry", as it's known, has been of particular interest to psychologists because it shows how the same incoming sensory information can give rise to two very different conscious experiences. Now, in a research first, psychologists have shown that a similar process occurs with our sense of smell. If one odour is presented to one nostril and another odour is presented to the other nostril, a person will experience "binaral rivalry" - sensing one smell and then the other, backwards and forwards, rather than a blending of the two.
Wen Zhou and Denise Chen presented twelve participants with the smell of rose to one of their nostrils and the smell of a marker pen to their other nostril. The odours were presented intermittently, every twenty to thirty seconds, to prevent "adaptation", which is the tendency for brain cells to gradually reduce their response to a continuous stimulus. After each break in the smells, the participants indicated on a visual scale whether they had detected the scent of rose or of marker pen. Just as with binocular rivalry, the participants' perceptual experience fluctuated back and forth randomly between the two scents.
The researchers believe this nostril rivalry is related in some way to the process of adaptation, both in the receptor cells in the nose and in the part of the brain that processes smells. For example, when repeatedly presented with a balanced mix of both smells, the participants' sensory experience fluctuated between rose and marker pen, presumably because of adaptation in the brain: as central neurons tired of one odour, their response to the other became more dominant and back again. The researchers also showed that adaptation occurs in the nose: swapping the bottles of odour around from one nostril to the other reinstated participants' experience of a given smell after it had previously faded through continuous sniffing.
"Our work sets the stage for future studies of this phenomenon," the researchers said.
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Zhou, W., & Chen, D. (2009). Binaral Rivalry between the Nostrils and in the Cortex. Current Biology, 19 (18), 1561-1565 DOI: 10.1016/j.cub.2009.07.052
Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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Neuroscience
Competition between nostrils
Show one image exclusively to one eye and a different image exclusively to the other eye and rather than experiencing a merging of the images, an observer's percept will flit backwards and forwards randomly and endlessly between the two. This "binocular rivalry", as it's known, has been of particular interest to psychologists because it shows how the same incoming sensory information can give rise to two very different conscious experiences. Now, in a research first, psychologists have shown that a similar process occurs with our sense of smell. If one odour is presented to one nostril and another odour is presented to the other nostril, a person will experience "binaral rivalry" - sensing one smell and then the other, backwards and forwards, rather than a blending of the two. Wen Zhou and Denise Chen presented twelve participants with the smell of rose to one of their nostrils and the smell of a marker pen to their other nostril. The odours were presented intermittently, every twenty to thirty seconds, to prevent "adaptation", which is the tendency for brain cells to gradually reduce their response to a continuous stimulus. After each break in the smells, the participants indicated on a visual scale whether they had detected the scent of rose or of marker pen. Just as with binocular rivalry, the participants' perceptual experience fluctuated back and forth randomly between the two scents.
The researchers believe this nostril rivalry is related in some way to the process of adaptation, both in the receptor cells in the nose and in the part of the brain that processes smells. For example, when repeatedly presented with a balanced mix of both smells, the participants' sensory experience fluctuated between rose and marker pen, presumably because of adaptation in the brain: as central neurons tired of one odour, their response to the other became more dominant and back again. The researchers also showed that adaptation occurs in the nose: swapping the bottles of odour around from one nostril to the other reinstated participants' experience of a given smell after it had previously faded through continuous sniffing.
"Our work sets the stage for future studies of this phenomenon," the researchers said.
_________________________________
Zhou, W., & Chen, D. (2009). Binaral Rivalry between the Nostrils and in the Cortex. Current Biology, 19 (18), 1561-1565 DOI: 10.1016/j.cub.2009.07.052Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.
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The novelists had it right - fear really can fill the air. Research shows smelling the odour of a scared person triggers activity in a swathe of emotion-related regions in the brain of the sniffer, and leads them to sniff harder and express a fearful...
- Empathic People Remember Your Smell
If you're an empathic person, able to tune into other people's feelings, then the chances are you've also got a keen sense of what other people smell like! We've known for some time that the brain areas involved in empathy and recognising...
- Fear Really Does Have A Smell
People often talk with some drama about the smell of fear, and yet who among us could describe what the odour is like? This vagueness seems to support the idea that fear as a smell is metaphorical - a way raconteurs through the ages have conveyed the...
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We share more in common with mice than a penchant for cheese, we also like the same kinds of smells. This suggests that our nasal preferences, even for biologically insignificant smells, are somewhat hard-wired or predetermined, and not entirely...
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Watch any dog sniffing its way down the street and it’s obvious they’re expert at localising smells. They seem to know which direction a smell is coming from, much as we do with sounds and, of course, sights. We can certainly tell where a smell is...