For years, researchers have been exploring the impact of smells on learning and memory. In one study,23 the odors of pine, peppermint, and osmanthus were used to determine if odor had an impact on the brain. In the testing, subjects were taken into a room where an odor was present and attention called to the smell. Each person was then left in the room for 10 minutes while he or she filled out a questionnaire. Following the questionnaire, the experimenter read a series of 20 common nouns. After each word, subjects were asked to describe some event that the word reminded him or her of. Forty-eight hours later, each subject was tested to see how many of the words could be recalled. When the unusual odor of osmanthus was present during the learning (when words were read and mentally imprinted) and testing, recall was best. Of the other two odors, recall was better when peppermint was introduced in a contextually inappropriate manner. Based on this study, the researchers determined that smell is a good contextual cue for learning.
In another experiment by Dr. Herz,24 40 students were given a word test for which they were not told they would need to recall the words later. Half of the subjects were in a room with no smell and the other half were in a room that smelled of violet leaf (an unusual and unpleasant odor). Seven days later, all students were tested in the same environments in which they had learned the words. Those who had been in the violet scented room did significantly better on recall than those in the room without an odor.
Dr. Alan Hirsch has also found a direct link between odors and mental processing. In a variety of studies, he found that environments with floral odors increased creativity, learning, and thinking ability.25 A similar finding occurred when a floral odor was introduced as subjects took the Halsted-Reitan Test Battery. In that study, 17 percent of the subjects completed the test faster when the fragrance was present.26
Shimizu Technology Center in Japan has also conducted studies to determine how smells influenced workers. That experiment involved the introduction of different fragrances into a work area where keypunch operators were positioned and monitored for entry errors. The results showed that:
Keyboard errors dropped 21 percent when a lavender fragrance (a relaxant) was introduced.
Errors dropped 33 percent when a jasmine (an uplifting scent) fragrance was introduced.
Errors dropped by 54 percent when a lemon fragrance (sharp, refreshing, stimulating odor) was introduced.27
Other researchers have found that women are more sensitive to odors than men and that smells definitely impact levels of relaxation and agitation. In addition, when bursts of peppermint or lily of the valley odors were introduced every 5 minutes as subjects complete certain tests, performance jumped as much as 15-25 percent. Also, when spiced apple scents are encountered, brainwaves and blood pressure drop within 1 minute.
Overall, it appears that pleasant, natural aromas increase efficiency and encourage more risk taking. They also cause people to negotiate more amiably, form more challenging goals, and behave less combatively.28
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