Thanks to our clever brains, we don’t notice it right away. two nostrils In fact, they function independently in some ways and seem to have their own sense of smell.
That’s the conclusion of a new study by US researchers that could tell us even more about the brain and how it processes the senses.
The findings are built on: previous research This shows that our brains are not only able to process input from each nostril individually, but may also be able to integrate them into one complete whole.
“Despite extensive research on odor responses in the olfactory system, little is known about how information from the two nostrils is integrated and differentiated in the human olfactory system.” write The researchers state in their published paper:
To further investigate the sense of smell in stereo, researchers from the University of Pennsylvania, Barrow Neurological Institute, and Ohio State University enlisted the help of 10 epilepsy patients who already had electrodes implanted in their brains.
One of three different scents and a control consisting of pure air were blown into one or both nostrils on each trial. After a few seconds, subjects were asked to identify the odor and state which nostril they used to detect it (left, right, or both). Meanwhile, the researchers collected data on brain responses via electrodes.
The research team made a number of interesting observations. For example, when the same odor was presented to each nostril in turn, the resulting brain activity was similar but not identical, suggesting some degree of independence.
Furthermore, sniffing the two nostrils together produced two distinct bursts of activity. Although the time difference between the two was very short, it did exist, and the researchers suggest that this also indicates that the nostrils do not always coincide.
Two nostrils are better than one when it comes to identifying smells and identifying them faster; This suggests that there is definitely some benefit to having one.
The analysis focused on: piriform cortex (PC) Brain area where olfactory sensations are processed and interpreted. As we already know, our various senses are also closely interconnected, so the findings could have implications beyond the sense of smell.
previous research The rats used both nostrils to discern where odors were coming from, showing they could “sniff in three dimensions.” The team behind this new study now wants to investigate whether this also occurs in humans, and how timing differences and nostril ‘smell coding’ are processed in the brain.
“Odor information originating from the two nostrils is temporally separated in the human piriform cortex.” write The researchers state in their published paper:
“Our findings have important implications for odor coding in the olfactory system, providing evidence that human PCs maintain a distinct representation of odor information originating from each nostril through temporal separation. ”
This study current biology.
