We tested to see if reaction rates were affected by blood pressure.  Blood pressure measures the amount of pressure exerted by one’s blood on the walls of his/her arteries. Two numbers go into measuring blood pressure – systolic and diastolic. Systolic corresponds to the pressure when the heart contracts, pumping blood to the body. Diastolic corresponds to the pressure as the heart relaxes between each contraction (American Heart Association). The ratio of systolic to diastolic is the final measurement of one’s blood pressure. An increase in blood pressure should increase the blood flow to the brain as well as to the rest of the body.  From this we hypothesized that more oxygen to the brain (caused by an increase in blood pressure) would improve reaction time.

            We only tested females to eliminate the possible variability between males and females. We measured each subject’s blood pressure and heart rate while sitting down and then measured their average reaction rate using a reaction timer. We then had each subject perform fifteen jumping jacks, measured their blood pressure and heart rate while standing and then again measured their average reaction rate.

            Linear regressions comparing blood pressure to reaction rates and heart rate to reaction rates showed no significant difference between reaction rates with lower blood pressure or heart rate and reaction rates with higher blood pressure and heart rates. Our P value comparing reaction rates to blood pressure was 0.346 and our R squared value was 0.049.  Our P value comparing reaction rates to heart rate was 0.710 and our R squared value was 0.0078. Clearly our results are not significant.

            Our average reaction time for higher blood pressure and heart rate was slightly lower than our average reaction time for normal blood pressure and heart rate, but still our averages didn’t show a significant difference. Our results did not support our hypothesis.  The way of increasing blood pressure may not have been very accurate as well as our actual measurements. The same goes for our measurements with reaction rates. Subjects differed as to how far their hands were from the reaction timer and this could have influenced their results. Also, we had a very small sample group. In order to obtain accurate data for human subjects we would have needed many more than 10 subjects. 

            A study by the Department of Psychology at George Washington University in October 2006 showed significant results when comparing blood pressure and cognitive performance.  Their results showed that “Lower blood pressure correlates with poorer performance on visuospatial attention tasks in younger individuals” (ScienceDirect).  They used 105 healthy young adults and had many more reaction tests.  We were unable to disprove our hypothesis; however, if we had more time and more tests we might have been able to come up with significant results. If we were to continue with this project we might want to focus on heart rate and reaction rates as well as testing the differences between males and females.   

           


 

 

 

 

 

 

 

Bibliography

 

"Blood Pressure." American Heart Association . 14 Nov. 2007 
               <http://www.americanheart.org/presenter.jhtml?identifier=4473>. 

 

Whartona Whitney, et al. “Lower blood pressure correlates with poorer performance on

            Visuospatial attention tasks in younger individuals” ScienceDirect 73.3 (May           2006): 227-234. 14 Nov. 2007             <http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T4T-            4JYKMTC1&_user=918210&_coverDate=10%2F31%2F2006&_rdoc=1&_fmt=            &_orig=search&_sort=d&view=c&_acct=C000047944&_version=1&_urlVersio            n=0&_userid=918210&md5=b640063481741a2a88653ec80fd0859e#secx28>