Science of Scent

Behaviors…Emotions…Perceptions

Olfaction, the sense of smell, is the detection of chemicals dissolved in air. Smells are sensed by the olfactory epithelium located in the nose and processed by the olfactory system. The accessory olfactory system senses pheromones.

The olfactory system must accomplish several tasks:

• Create a representation of the odor
• Determine the concentration of the odor
• Distinguish a new odor from the background environmental odors
• Identify the odor across different concentrations
• Pair the odor with a memory of what the odor represents

To accomplish all of these functions, the olfactory system uses many areas of the brain.

Odor information is easily stored in long term memory and has strong connections to emotional memory. This is possibly due to the olfactory system's close anatomical ties to the limbic system and hippocampus, areas of the brain that have long been known to be involved in emotion and place memory, respectively. The other senses of sight, sound, taste and touch take a convoluted route through the left-brain’s interpretive center.

When we see, hear, taste or touch, we analyze the information first. When we smell, we immediately obtain a feeling or memory.

Smell is extremely important for taste. The human tongue can only sense 4 different things (some studies say 5, 6 even 7, but still a limited number), while the nose can sense many thousands. This is the reason why you can taste very little when you have a blocked nose.

Research into scent and smell is relatively new.

Although perfume and aromas have been used for centuries in healing, soothing, religious rites and rituals, scientific researchers have only recently become aware of the broad impact that scent plays on human behaviors and emotions. In 2004, doctors Linda B. Buck and Richard Axel were awarded a Nobel Prize for their discoveries of odorant receptors and the organization of the olfactory system.