People with anxiety have a better sense of smell when it comes to detecting a threat, according to a new study by the University of Wisconsin-Madison.
Similar to what happens in animals, smells evoke a strong emotional response in humans. Researchers Elizabeth Krusemark and Wen Li hypothesized that in humans, smelling an especially bad stench may alert the brain to a poisonous airborne substance or a decaying object that carries disease.
For the study, 14 young adult participants were exposed to three types of odors: neutral pure odor, neutral odor mixture, and negative odor mixture. While being examined with an MRI scanner, volunteers were asked to identify the presence or absence of an odor.
During scanning, the researchers also measured the skin’s ability to conduct electricity (an indicator of arousal level) and tracked the participants’ breathing patterns. After the odor was eliminated, and the participants were still being scanned, they were asked to rate their current anxiety levels.
As researchers evaluated the brain images, they discovered that as participants’ anxiety levels rose, so did their ability to decipher bad odors correctly — suggesting an extremely enhanced olfactory ability in anxious subjects. The skin conductance test also revealed that anxiety heightened emotional arousal to smell-induced threats.
In conclusion, the results show that during a state of anxiety, there is stronger communication between the sensory and emotional areas of the brain in response to negative odors. This increased connectivity may be responsible for the heightened arousal to threats.
The researchers say that this enhanced sensory-emotional connection could be a critical function, designed to arouse physiological alertness to potential threats.
The research is published online in Springer’s journal Chemosensory Perception.
Source: University of Wisconsin-Madison