Making Sense of Smell
How does smelling work?
- Outside stimuli is attracted into the outer part of the nose.
- The stimuli (tiny particles that travel through air) travel up the nose to cilia (hair-like structures at the top of the nasal passages. The cilia are like taste buds and change every few weeks and can sense over 1,000 different smells.
- There is 10 million receptor sites on the cilia that process the stimuli send into to the brain.
- The smell is processed in the olfactory bulbs right beneath the frontal lobe. The thalamus sends information to other parts of the brain.
Basic Smell Principles of Sensory Transduction
Sensory transduction is the process of changing stimuli into neural activity.
- Absolute threshold is the lowest amount of stimulation that can be detected. For example, a drop of perfume in a three room apartment.
- Difference threshold is the smallest difference between two stimuli.
- Sensory adaption is when a stimuli becomes less noticeable the longer it happens for.
- If a neighborhood smells like oil because of the oil refinery down the street, a resident would get used to it.
- A smell can affect behavior; if someone sniffs then more of the molecule making the scent is getting information to the brain. If a scent is bad it can cause a person to be more keen on getting away from it. For example a skunk hit by a car make cause the people in the surrounding area to not go outside. If a bakery just bakes fresh bread, then the passerby may walk into the bakery.
- Sense of smell allows a perception of the world that can help a person live in an environment. If someone smells gasoline in a house, then they may want to leave because of a gas leak.
- Olfaction- the sensation of smell
- Process of smelling-particles traveling through the nose to the cilia to receptor cites to the olfactory bulbs to the brain.
- Olfactory bulbs-areas of the brain locate just above the sinus cavity and just below the frontal lobes that receive information from the olfactory receptor cells.
- Anosmics/hyposmia- hyposmia is a reduced ability to smell and detect odors. Anosmics is when no odors can be detected.
- Pheromones- chemicals that are secreted in our sweat and other bodily fluids that are believed to influence the behavior of the opposite sex, such as triggering sexual interest and excitement.
- Nasal cavity-large air space above and behind the nose in the middle of the face.
- Aromatherapy-practice of using natural oils to enhance psychological and physical well-being.
- Effect of smell on emotions- how something smells or how someone smells can affect our perception of that thing or person. For example the smell of fresh baked bread can result in a person wanting bread. Also women often are more attracted to men who smell good.