Exercise Two: Perception and Cognition Research (Smell)

Exercise Two: Perception and Cognition Research (Smell)
Desiree Beaubien & Bradley Crystal

In many cases, smell is the first of the senses to respond to stimuli. It prevents us from drinking rotten milk and it warns us if there is fire. Such odors and many others are detected by sensory cells called Chemoreceptors.

Chemoreceptors which are made up of about five million nerve endings and make up a patch about the same area as a quarter, detect odor molecules in the air. At the end of each nerve is a knob shaped Dendrite. Dendrites sends electrical pulses through axons into the Olfactory Bulb. Some of the nerves which transmit information to the Olfactory Bulb are responsible for transmitting odor information while others are responsible for transmitting pain information. This is why when the odor of a chemical such as Ammonia is inhaled, the body feels a stinging pain. This is the body's natural response to what may cause harm.

The Olfactory Bulb is part of the brain's Limbic system. This area is responsible for memory and emotion. The Bulb has direct access to the part of the brain which is responsible for associative learning which creates conditioned responses. Every time the body encounters a new smell, it is linked to an even, person or place and a link is forged by the brain. When the smell is encountered again, the brain can instantly recall the memory or emotion associated with it.

Source: How Stuff Works - http://images.google.ca/imgres?imgurl=http://static.howstuffworks.com/gif/pollution-sniffer-2.gif&imgrefurl=http://science.howstuffworks.com/pollution-sniffer1.htm&usg=__JP6U77MpiqNc9_UMeFh-i1IgeRg=&h=296&w=400&sz=48&hl=en&start=3&um=1&tbnid=VlEBnRCz_Ji65M:&tbnh=92&tbnw=124&prev=/images%3Fq%3Dolfactory%2Bdiagram%26um%3D1%26hl%3Den%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official%26sa%3DG