Conclusion

The purpose of this lab was to understand how different stimulants (caffeine, guaranine, and ginsenosides) affect blood pressure, reaction time, and pupil dilation size. The research question was: How will caffeine, guaranine, and ginsenosides affect the central and peripheral nervous system (Reaction time, blood pressure, and pupil dilation)? It was hypothesized that caffeine would increase reaction time, pupil dilation size, and both systolic and diastolic blood pressure, guaranine would have similar, yet weaker effects than caffeine and ginsenosides would only slightly increase blood pressure and reaction time, but pupil dilation size would be unaffected. First, a subject will take 200 mg of caffeine. The subject will wait 10 minutes. The subject will then have their blood pressure measured. The subject will have their pupil dilation measured. The subject will then have their reaction time measured. He will wait a day. This is then repeated the next day with guaranine and the day after with ginsenosides. Results showed that caffeine raised systolic blood pressure, increased reaction time, and increased pupil dilation size. Similar results occurred with guaranine, yet it was weaker. Ginsenosides decreased blood pressure, greatly increased reaction time, and decreased pupil dilation size.

Results were similar to the hypothesis. With caffeine, average systolic blood pressure increased by 12 psi. With guaranine, average systolic blood pressure increased by 8 psi. With ginsenosides, average systolic blood pressure decreased by 14 psi. Caffeine increased reaction time by 2 cm. Guaranine increased average reaction time by .5 cm. Ginsenosides increased average reaction time by 3 cm. Caffeine increased average pupil dilation size by 3 mm. Guaranine increased average pupil dilation size by 1 mm. Ginsenosides decreased average pupil dilation size by 1.7mm.

Some errors that could have occurred in this lab would be eating something that would have increased blood pressure before taking the stimulant. For example, highly salted foods are known to increase blood pressure. Another error that could have occurred would have been not waiting long enough between the stimulant dosage and the testing.

An extension to this lab would be using a wider variety of stimulants that affect different receptors, such as dimethylamylamine. Another extension to this lab would be using more tests that require the use of the central and peripheral nervous systems. A test that could have been used would be grip strength.

This study is relevant to society because 99% of the U.S. population uses one or more of these stimulants. Many people do not understand that many stimulants change blood pressure. This study also helps people understand that stimulants change pupil dilation size. If somebody is out in the dark, he or she may want to take a stimulant that increases pupil dilation size. Basically, this study can help people choose a stimulant that has little detrimental effects to one's health, yet can help increase reaction time and help people see in the dark by increasing their pupil dilation size.