1. Karen Bowman, Sarah Brown, Kristin Howell, Melinda Simpson
Individual Differences in Sympathetic Nervous Response to Cold Temperature
Karen Bowman, Sarah Brown, Kristin Howell, Melinda Simpson
ABSTRACT
METHODS
The purpose of the experiment was to compare the average heart rate and respiration rate of identified “Flight” and “Flight” participants (Flighters and Fighters) after exposure to extreme cold. Each participant’s heart rate and respiration rate was measured before and after their dominant hand was submerged in an ice bath. The results of the experiment indicated that there was no statistically significant difference between the” Fight” and “Flight” Group in either heart rate or respiration rate. Persons identified as having the “Fight “ response had the same response to extreme cold as persons identified as the having the “Flight” response.
Participants completed an online assessment to identify them as “fighters” (n= 6) or “flighters” (n= 2).
Participants were connected to a Logger Pro respiration belt to measure respiration (breaths/minute) and hand-grip heart rate monitors to measure heart rate (beats/minute).
Baseline heart rate and respiration rate were collected for 30 s.
Participants placed their dominant hand in a bucket of ice for 30 seconds. Immediately after, heart rate and respiration rate were collected for an additional 30 s. Each participant completed two trials.
An independent t-test (α = 0.05) was used to compare the average increase in heart rate and respiration rate between “fighters” and “flighters”. (Ho= μ1=μ2, HA= μ1≠μ2)
Participants were attached to a respiration belt with gas pressure sensor, and hand-grip heart rate monitor to measure breathing rate and heart rate, respectively. Responses were compared before and after exposure to the ice bucket.
T-statistic
Degrees of Freedom
Critical Value
Conclusion
Heart Rate
0.110 6
2.447
Fail to Reject Null
Respiration Rate
0.088
PURPOSE
Change in Heart Rate (beats/min) Following Cold Exposure There was not a significant difference in heart rate (beats/min) between the “fighters” (M= , SD= ) and “flighters” (M= -0.25, SD= 1.061); t(6)= 0.110, p>0.05.
The aim of this experiment is determine if there are differences in the sympathetic nervous response between individuals identified as “fighters” or “flighters”. We predict that when exposed to extreme cold, there will be a difference in heart rate and respiration rate between “fighters” and “flighters”.
DISCUSSION
Our results suggest that there is not a significant difference in the sympathetic nervous response between individuals identified as “fighters” and individuals identified as “flighters”. This did not support our hypothesis.
The validity of our results may have been influenced by small sample size, and would need to be repeated with more participants. Also, complications with equipment led to outliers in data calculation, which accounted for the large variance. In addition, the online assessment exposed bias in the participants selection.
In future experiments, we could increase exposure time and control for confounding variables (e.g. caffeine intake). We can also personalize the stressors to the participants to exaggerate their sympathetic response.
BACKGROUND
The sympathetic nervous system is a division of the autonomic nervous system responsible for stimulating the “fight or flight” response.1
This system activates the adrenal medulla to release norepinephrine and epinephrine into the bloodstream to accelerate heart rate and breathing rate.2
Individuals identified as “fighters” produce a defensive or aggressive response to stressors, where than individuals identified as “flighters” will attempt to avoid the stressor.
Change in Respiration Rate (breaths/min) Following Cold Exposure There was not a significant difference in respiration rate (breaths/min) between the “fighters” (M= 5.167, SD= ) and “flighters” (M= 6.25, SD= 3.182); t(6)= , p>0.05.
References
1. Wikipedia.  (2016, May).  Sympathetic nervous system.  Retrieved from  
2. Layton, J. (2005, September). How fear works. HowStuffWorks.com. Retrieved from
Acknowledgements
We would like to thank Master PLTW Teacher Angela Lewis and our participants