Psychology

Olfaction is basically the sense of smell of creatures that breath air. For humans, smell relies on sensory receptors that react to volatile chemicals in the air. These receptors, known as chemoreceptors, are situated in the olfactory epithelium, which is a piece of tissue situated in the persons nasal cavity. People can easily notice the power and importance of this tiny tissue when it filters certain smell and reminds them of some memory of other people they met in the past or certain occasions that have happened to them. In fact, in most cases, it only takes the slightest indication of aroma to bring a memory to the head of the exposed person. Because of this marvelous observation, numerous physio-psychologists, biologists, and psychologists conducted a number of diverse types of experiments in order to give explanation to the connection between the memory and smell.

Studies about Human Sense of Smell
Humans are capable of memorizing either intentionally or incidentally different types of odors. However, in many cases, odors are learned unintentionally as people do not normally take time to memorize scents. In a number of studies, visual and verbal signals are found to create some type of connection between the memory and olfaction. These studies include the Hebbian Principle and Autobiographical Recall (Dill, 2007).

The Hebbian Principle
The Hebbian principle applies to olfactory stimuli when odors are learned through repeated exposure. To illustrate, the major difference between a persons ability to identify odors and faces is that every person has expectedly acquired an enormous proficiency in recognizing faces. This observation could be due to the fact that sense of smell is not as essential in peoples everyday life. However, the human sense of smell has much more power than what people normally believe. Although people are not capable of distinguishing specifically many odors, if learned, peoples ability to distinguish odors is remarkably comparable to their ability to distinguish faces. People are basically expected to retain information more effortlessly when frequently detected, and olfactory memories are not an exemption (Dill, 2007).

In one study conducted by Egon Peter Koster, Jochim Degel, Clair Sulmont, Dominique Valentin, and Sylvie Issanchou, they concurred that faces and odors have several significant common features even though they are apparently very different stimuli (as cited in Dill, 2007, p. 2). Odors and faces elicit emotions and provide social signals that are not easy to disregard once learned. This context-dependent memory is known as perceptual learning, which is learned through repeated exposure (Dill, 2007, p. 2).

Autobiographical Recall
Larsson and Willanders studies about autobiographical memories reveal that olfactory-evoked memories largely recall memories that occurred during ages 6 to 10 in contrast to 11 to 25 for verbally-signaled memories (as cited in Dill, 2007, p. 4). In view of this, memories evoked by visual and verbal signals are basically pulled out from young adulthood, while memories linked to odors are linked to the first decade of a persons life. In other words, olfactory-cued autobiographical memories are older than memories connected with verbal-signals. Odor-related memories therefore arouse more intense feelings of being transported back in time.

Connection between Smell and Memory
The olfactory bulb is part of the limbic system of the brain, an area intimately connected with feelings and memory. The olfactory bulb has close contact with the hippocampus, which is in charge of associative learning, and the amygdala, which processes feeling. Because of such association, smell can activate immense reactions and memories almost instantly. When a person smells a new scent, he or she unconsciously associates the scent with a thing, person, or event, and as a result, the persons brain creates a connection between a memory and the smell.

Smell is a very important aspect of human episodic memory. A smell can trigger thoughts, mental images, and emotions that people associate with previous events, persons, or things. The brain initially figures out the earliest specific scent obtained by the olfactory sensation and eventually associates it with something. In time, the scent can trigger several regions of the brain that can remind the person of the event, thing, or other person originally associated with the smell. Unpleasant or noxious odors, for instance, can make a person ill or unhappy, while pleasant aromas can elevate mood. Because people encounter many new odors during their early days, smells normally generate childhood memories.

Conclusion
Olfaction is also known as the sense of smell, which is a basic sense of humans. Although the olfactory system of humans is not designed to identify odors, it can distinguish between odors through repeated exposures. This exceptionally amazing feature of the human sense of smell can affect autobiographical recall as well as memory-related learning. Accordingly, certain smell can affect peoples work performance, influence their moods, and even bring several memories. Because of the mystery between the link of smell and memory, throughout the years, it has been the subject of numerous neurological researches of physio-psychologists, biologists, and psychologists, many of which produced relevant answers.