It is not the senses of hearing or sight as many believe; a recent Swedish study has revealed another sense in the human body that serves as a stronger alarm system, helping individuals avoid risks. According to the scientific site "Noon," the National Academy of Sciences at the Karolinska Institute in Sweden published the results of a study conducted by researchers to uncover how humans respond to negative odors that may indicate potential dangers.
The study indicates that the olfactory organ occupies about 5 percent of the human brain and allows us to distinguish millions of different odors within 100 to 150 milliseconds. The vast majority of these odors pose a threat to human health or life, such as the smell of chemicals or spoiled food.
However, the challenge lay in understanding how olfactory nerve cells function, which has become a puzzle for researchers due to the lack of methods to measure the signals sent from the olfactory bulb (the smell processing area in the brain) through important central parts of the nervous system that help us detect and remember situations or substances that threaten our lives.
The site "Noon" cites the scientific site "Science Daily," noting that for the first time, a transformation has occurred as the researchers at the Karolinska Institute agreed on a method to measure the signals from the olfactory bulb and convert them into commands in the parts of the brain responsible for movement and avoidance behavior to evade threats.
During the study trials, researchers asked participants to evaluate their feelings after inhaling six different odors, both positive and negative, while measuring the olfactory bulb's response to each one.
Johann Lundström, one of the researchers in the study and an associate professor in the Clinical Neuroscience Department at the Karolinska Institute, commented, “It was clear that the olfactory bulb responds immediately to negative odors and sends signals to the motor cortex within 300 milliseconds to prompt the individual to involuntarily retreat from the source of the smell.”
Lundström added, “The results affirm that the sense of smell is very important for identifying danger in our surrounding environment, even surpassing the senses of sight and hearing concerning our rapid responses to sources of danger.”
