Soothing Scents: Smells of Nature Lower Physiological Stress

In a virtual reality experiment, people recovered faster from a small electric shock when they smelled a mix of natural scents in a forest scene or grass in a park scene than when they smelled diesel or tar in an urban setting. Researchers at the Swedish University of Agricultural Sciences hypothesized that natural environments would reduce stress faster than a non-natural one. After administering the small shock to induce stress, they tracked how quickly participants’ skin conductance levels rose and fell in each of the three environments. The pleasant natural scents were the strongest predictor of reduced stress, both during the initial shock response and in recovery, suggesting that odor might have a much more profound effect on reducing stress than sights and sounds. As study coauthor Johan Lundström, a neuropsychologist at Sweden’s Karolinska Institute, theorized smell is wired to bypass the thalamus, the brain’s switchboard, to go directly to the hypothalamus and olfactory cortex, creating a more immediate response than visual or auditory stimuli.