Activity
Hearty Smells
Science experiment for students who are blind or visually impaired to study how smell affects heart rate and stress.
This science project was done by Donna, who is a student at Texas School for the Blind and Visually Impaired (TSBVI).
Question
Does smell affect heart rate and cause stress?
Note: why does heart rate speed up when we are stressed?
Smells:
- Lavender
- Lemon oil
- Coconut oil
- Vineger
- Tea tree oil
- Cinnamon
Research
Odor facts: Younger people are more sensitive to odors than older folks. Women are more sensitive to odors than men. Non-smokers are more sensitive to smell than smokers. People with an empty stomach are more sensitive to odors than people who just ate. People are more sensitive to odors in the morning than in the evening.
Odors can affect behavior; Mood, level of alertness, levels of anxiety, level of stress.
Unpleasant or Negative odors can have a negative health impact; nausea, headaches, depression, increased anxiety, Elevated blood pressure, decrease in physical energy, compromise immune system, physical discomfort, increase in anger and stress, and muscular, control problems fatigue and confusion.
Hypothesis
If someone smells a pleasant smell I believe that their heart rate would heart rate and blood pressure would calm or slow down. If someone were to smell an unpleasant smell I believe that their heart rate and blood pressure would increase.
As I researched this topic, it became more complicated because not all people consider the same smells pleasant or unpleasant. For instance, one of my volunteers found tea tree oil to be a pleasant smell, even though I had chosen it as an example of an unpleasant smell.
Materials
digital heart rate reader - lavender essential oil
- coconut oil
- tea tree oil
- cinnamon essential oil
- vinegar
- lemon essential oil
- blindfold
- 6 jars with lids
- volunteers
Step 1. Ask student if they are allergic to anything. Blind fold the person alone in a room allow 2 minutes for student to calm down before taking measurements.
Step 2. Take heart rate before procedure begins.
Step 3. Have person smell lavender 5 seconds then lemon, next vinegar, after coconut oil, then tea tree oil, and finally cinnamon.
Step 4. Between each scent record heart rate 7 seconds after smelling the scents. wait 5 minutes between each scent.
Results
Average change of heart rate in beats per minute
Cinnamon – Decrease of 5.8 BPM
Lavender – Decrease of 1.1 BPM
Lemon – Increase of 2.5 BPM
Coconut Oil – Increase of 3.9 BPM
Tea Tree Oil – Increase of 5.2 BPM
Vinegar – Increase of 6 BPM
Comments from Students:
About Vinegar:
- “That hurt my tonsils and tongue.”
- “Oh no miss, that burned my nose Miss”
- “This one is rank.”
About Tea tree oil:
- “That stinks. I hate you, you.”
- “ This smells like a nursing home.”
About Lemon:
- “That reminds me of that that cleaning stuff.”
About Coconut oil:
- “I can’t smell nothing , It’s faint.”
About cinnamon:
- “Smells like a sports place.”
About lavender:
- “Am I going to die because my heart dropped 2 beat
Conclusion
My results were inconclusive as I discovered that smells are very personal. What is a pleasant smell for one person may be an unpleasant smell for another.
Variations
Other scents were considered including sulfur which smells like rotten eggs.
NGSS Standards:
- Plan and conduct an investigation individually and collaboratively to produce data to serve as the basis for evidence, and in the design: decide on types, how much, and accuracy of data needed to produce reliable measurements and consider limitations on the precision of the data (e.g., number of trials, cost, risk, time), and refine the design accordingly. (HS-ESS2-5)
By Laura Hospitál
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