Smell is one of the most powerful sense for evoking memories and emotions. But researchers have discovered that stress and rewire the brain to make even benign odours stink.
Scientists from the University of Wisconsin-Madison used brain-imaging technologies to discover how smells influence emotional centres in the brain. People in the study were asked to look at disturbing words and pictures, and were then exposed to some neutral smells before having an MRI scan. As their stress and anxiety increased, their reaction to these neutral smells became more negative. The study showed the researchers that two independent circuits of the brain — one for processing smells, the other for emotion — “become intertwined under conditions of anxiety”.
Professor of psychology Wen Li, who led the study, says: “After anxiety induction, neutral smells become clearly negative. People experiencing an increase in anxiety show a decrease in the perceived pleasantness of odours. It becomes more negative as anxiety increases. We encounter anxiety and as a result we experience the world more negatively.”