HBS, period 1
Reaction time experiment
Caffeine and Reaction Time
1) Identify the Problem or Question
How does the consumption of caffeine affect the reaction time of the nervous system?
Purpose of the experiment: To identify the whether or not caffeine increases or decreases the reaction time of the nervous system.
In our experiment, we have decided to use all the “cases” which will test how fast a signal from our brain will be sent to our muscles in order to click the mouse when we see an object or directions on the screen. We know that the commonly used drug, caffeine, increases the heart rate, thus the increase in blood flow. The question in our experiment is, does the increase of blood flow, caused by caffeine, positively or negatively affects the reaction time that it takes to click the mouse the moment we see an approaching object.
Another underlying factor we can analyze in our experiment is gender and age. Since we are using test subjects whose ages and gender vary from 16 to 50 and from male to female, we can roughly conclude whether or not age and gender affect reaction time. The reason we say roughly, is that the two factors, age and gender, are being “tested” in conjunction with the consumption of caffeine. We do not know if the consumption of caffeine and its effects vary for how old the person is and his or her gender.
3) Research and Current Ideas
In past experiments, people have concluded that there is an inconsistency in results depending on the amount of caffeine consumed. Apparently, a half-cup of coffee had faster reaction times than the reaction times that were drawn when the test subject drank a full cup of coffee. The person had concluded that too much caffeine could actually impair reaction time, but the right dosage could potentially increase reaction time.
4) Predict a solution to the problem or an answer to the question
Scientific Hypothesis: The consumption of 12oz of ground coffee will speed up our reaction time. Using past experiments conducted by other people, and the chemical compounds of caffeine and its affects on our body, we have drawn this hypothesis.
Dependent Variable: Reaction time
Independent Variable: Condition of the test subject (Caffeine)
The reaction time is the dependent variable, because the results depend on the condition of our subject. The condition of the test subject is the independent variable because we are changing the state of our test subject by increasing their caffeine levels.
5) Design the experiment to be used to test your hypothesis
* 4 tablespoons/24 of Maxwell house coffee blend
* 4 test subject (2 16 year olds/ 2 middle aged adults, one of each gender) * Serendip software
1) Complete a control experiment by conducting the serendip experiment while you are in your natural state for each test subject. 2) The site for the serendip activity is: serendip.brynmawr.edu/bb/reaction/reaction.html 3) Make sure that each “Case” is done 10 times to ensure accuracy. 4) Click “Results Summary” and record the information given. 5) Have each test subject consume 12 oz (2 tablespoons) of the Maxwell House Coffee blend. 6) Wait five minutes before the test subject goes through the serendip reaction time activity again. 7) Repeat steps 1-3 for each test subject, except after he or she has consumed the coffee and waiting for a duration of 5 minutes before completing the serendip activity. 8) Record the results in a data table.
6) Carry out the experiment
| Control Experiment
| Experiment w/ Caffeine
| 219 +- 15 milliseconds
| 194+- 11 milliseconds
| 270 +- 32 milliseconds
| 243 +- 28 milliseconds
| Read, Think, Act
| 394+- 74 milliseconds
| 364 +- 68 milliseconds
| Read, Think-Negate, Act
| 383+- 102 milliseconds
| 352 +- 64 milliseconds
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