Emotion        

          According to the Social Issues Research Centre, the perception of smell not only is associated with odors but also is associated with experiences and emotions. This is because olfactory receptors are connected to the limbic system, the most primitive part of the brain, which is thought to be the root of emotions. Once smell sensations have been delivered to the cortex and we have correctly named the scent, the scent has also made an impact on the limbic system which triggers and emotional repsonse. 

 

          Pleasant fragrances often lead to positive emotions. In an experiment, when subjects were exposed to pleasant fragrances, they often gave higher attractiveness to people they viewed in photographs. The pleasant fragrance did not work if the people in the photos were very attractive or unattractive but if they were moderately attractive, the pleasant odor often tipped the scale in their favor and were seen as more attractive. Another experiment that used an unpleasant odor had a reverse effect. The unpleasant odor seemed to have led the subjects to give lower attractiveness ratings to the people they viewed in photos. This is showing that odors, regardless of pleasant or unpleasant, often cloud our judgement. 

 

Disgust is one of the 6 major emotions in humans. We display signs of disgust when we taste something bitter. The rejection of food is a defense mechanism to protect us from eating poisonous or spoiled foods. The anterior insula is the primary taste cortex and coincidentally, it is the focal neurological site for disgust processing. As well as disgust being activated by poisonous or spoiled foods, it is also activated by bodily fluids, death, disease, sexuality, and morality (Herz, 2014).

 

Mood-Effects

          An experiment using an odorless spray placebo showed that subjects did not respond to the placebo which they think are fragrances, The subjects did in fact respond to the thought of pleasant fragrance which improved the subjects mood and made them more cheerful but actually smelling the fragrance dramatically increased their mood.

          Another experiement used pleasant and unpleasant fragrances and stimulated the left and right nostrils. Differences in the olfactory neurons in the left and right hemispheres were found. This shows that positive emotions are oftten processed by the left hemisphere of the brain whereas negative emotions are often processed by the right hemisphere of the brain.