Methods
Study population
Undergraduate students at Clarkson University from various academic backgrounds are the focus of the experimentation. The three schools at Clarkson were used for this study, Engineering, Arts and Sciences, and the school of Business. A sample population of 2-3 students for each academic discipline was subjected to experimentation.
Experimentation
The subjects first filled out a consent form and pre experiment questionnaire both of which are shown in the appendix. All jewelry was removed from the volunteer’s hand and arm. Once subjects were completely hooked up, they underwent a 5 minute baseline test to measure their resting pulse, respiratory rate, EMG activity, adn skin conductance. The subject then practiced the game on the first 3 levels of the Kami 2 puzzles. The subjects were then instructed that they would have 15 minutes to solve 8 pre chosen levels of puzzles: page 2 level 4, page 3 level 3, page 4 level 6, page 5 level 5, page 6 level 4, page 7 level 6, page 9 level 3, and page 19 level 3 . Each level of puzzle progressed to a higher difficulty. Each subjects information was then saved under their test number and time the experiment occurred. The subjects were then disconnected from all of the PowerLab equipment.
Procedure 1, Respiration Set Up
The Respiratory Belt was connected into the input on the front panel of the PowerLab. The Belt was then attached around the volunteer’s abdomen where breathing change was most apparent with the writing on the belt facing outward. After turning the PowerLab on the volunteer was instructed to sit relaxed facing away from the monitor. When the start button for recording was pressed and the subject was asked to breathe rapidly for 5 seconds and then slowly for 5 seconds to ensure that the rate was properly displayed. The subjects were then instructed to breathe normally through their baseline. We talked to them throughout so they wouldn’t be thinking about their breathing so we could collect a typical baseline. After the experiment the respiratory rate was found by looking at the cyclic measurements and finding breaths per minute.
Procedure 2, Blood Volume Pulse Set Up
The Finger Pulse Transducer was connected to the input on the front panel of the PowerLab. The pressure pad of the Finger Pulse Transducer was then placed on the tip of the subjects non-dominant middle finger and held firmly in place with a velcro strap without cutting off circulation. The subject was then instructed to lay their hand on the table with their palm facing up and requested to not move their hand as much as possible. After the PowerLab was turned on the volunteer was instructed to face away from the monitor. After the signal was analyzed by looking at the beats per minute over the entire thing compared to their baseline. Each individual level was observed as well for heart rate.
Procedure 3, Skin Conductivity Set Up
The GSR Amplifier was connected to the PowerLab with the I\(^2\)C cable. Then the BNC cable was connected to the signal output on the GSR Amplifier and then was connected to input three on the PowerLab. The finger electrodes were then connected to the GSR Amplifier. Subjects were instructed to let their non-dominant hand rest palm up. The skin conductivity throughout the experiment was constantly compared to the baseline. If there was an increase then it indicated that a stress response was present.
Procedure 4, Electromyography (EMG) Set Up
The 5 Lead Shield Bio Amp Cable was connected to Bio Amp Connector on the front panel of the Powerlab. The hardware was connected prior to opening the settings file. The volunteer’s skin was abraded with abrasive gel. After abrasion, the area was cleaned to remove dead skin cells using a alcohol pad. A ballpoint pen was then used to mark four small crosses about 2-3 inches apart on the skin above the shin and the calf muscle. Once the skin was dry the disposable electrodes were connected to the skin at the points mentioned. The Shielded Lead Wires were connected to the Bio Amp Cable and then the electrodes were connected to the wires. The color scheme on the Bio Amp Cable was followed. The green Earth lead was attached to the Dry Earth Strap. The four electrodes and Dry Earth Strap were then attached to the volunteer. Channel 1 leads to the top of the shin a couple inches below the knee, channel 2 leads to the shin approximately 3 inches below the first. Then channel 3 was connected at the same height as channel 1 but on the calf muscle, channel 4 leads to the calf approximately 3 inches below channel 3. The Earth was connected to the Dry Earth Strap and placed around the ankle. The EMG was used to measure the movement of the leg and the tension placed there by stress. When stressed many people move muscles in their body to help relieve tension and that is what we are measuring through this experiment. The amount of tension throughout the experiment was compared to the baseline and the difference is what was analyzed.
Results
Effect of Stress on Heart Rate (Pulse)
The completion of the experimentation and analysis showed that the largest heart rate change in relation to the individual was 12% from baseline from one of the subjects. Three subjects had a 2% heart rate change from their baseline which was the lowest recorded change in all the subjects. Arts & Science students showed the largest average of percent change at 6%. The lowest average change was 2%, observed in Business students. Engineering students were closer to the Art & Science students at a 5% change.
Effect of Stress on EMG
Results from the EMG data show that engineering students had the lowest average change in EMG activity at a 7% change. Business students had the next lowest percent change at 10%, while arts and science students showed a 40% increase from their baseline to their testing measures. Three subjects all showed a 3% change, the lowest change seen, while one subject showed a 92% change.
Effect of Stress on Skin Conductivity
The largest percent change of data collected was recorded during the skin conductance. Business students were shown to have an average of 5.02 fold increase, the highest of the disciplines. Within that group, one subject showed a change of 10.03 fold increase. The highest individual change was of an engineer subject, with a change of 10.98 fold increase from baseline. This subjected noted at the start of the experiment that they have hyperhidrosis which was diagnosed by their physician. The engineer average change was a 4.24 fold increase. Art & Science students had the lowest average change of 96%. out of all the subjects a business student, subject 7, and a change of 1%.
Effect of Stress on Respiration
Analysis of this data showed that engineers had the lowest change in respiratory rate from their baseline at 15%. Arts and science students showed the largest percent change with a 37% increase in their respiratory rate, while business students averaged a 27% change. The lowest change was 2% increase seen in an engineering student, whereas the highest change was 76% seen in an arts and sciences student.
Kami 2 Gaming Performance
Out of the subjects one engineering student, made it to level 6 to attempt it. Due to time constraints, they had 17 seconds to solve the puzzle and did not succeed. Level 6 is the highest level achieved and was only done so once. Three subjects made it to level 5 with sufficient time to attempt the levels multiple times. Two of those subjects were arts & sciences majors and one was an engineering student. Two subjects were business students and both reached level 4. One subject did not have a sufficient amount of time to solve the puzzle in correlation to the average and the fastest time of those that did move on to level 5. The average time to complete level 4 was 78.4 seconds and the fastest time was 65 seconds. Two subjects did not complete level 3, however, they did have sufficient time to complete the level. Art and Science students had the fastest average on level 1 with 13.3 seconds followed by engineers with 19 seconds and business subjects with 19.5 seconds. Engineering students had the fastest times on levels 2,3 and 4 with business students being the slowest on 2 and 3 and not completing 4. Engineers also had the longest time on question 5 with an average of 608 seconds in comparison to the art and science average of 536.5 seconds. Business students ran out of moves and/or reset levels 1, 2 and 3 the most. Level 4 had the same average reset and out of turns by the business students and the art and science subjects. Engineers had 1 more average reset than art and science students on level 5.
Discussion
Each subject showed a change in each vital measured during the experiment. A change in vitals was expected for our experiment however, some vitals did not change in the manner that we expected. For subjects 3, 6, 7 and 8 heart rate was observed to reduce during the experiment. Out of these subjects, 6 and 7 show a reduction in respiration during the experiment as well. The reduced breathing may contribute to the heart rate reduction seen during the experiment. Subjects 3 and 8 may show a reduction because the subjects may find puzzle solving a means of relaxation. It was concluded that the subject's heart rate reducing due to rest could be eliminated from possible causes because the subjects had already been resting for over five minutes due to the collection of the baseline. Subjects 2,3 6,7 and 8 all showed a higher heart rate at the start of testing in comparison to their individual baseline. This may indicate the first onset of stress due to the start of the timed testing situation.
It was expected that business students would experience the greatest percent change from their baseline values but from the data analysis, the art and science subjects show the greatest change in every area except in skin conductance. Business subjects showed the greatest change in skin conductance and the second greatest change in electromyography and respiration. Subjects 4 and 5 both reported a diagnosis of anxiety on the pre-questionnaire. They also answered to have a 4 and 6 level of stress respectively. Both Subjects are art and science subjects. With this information it was concluded that the test does initiate stress in those with anxiety and the results are skewed because of these pre-existing diagnosis. The group with the most people with a diagnosed anxiety condition showed the greatest response to a stress response test. Taking this into consideration and excluding it due to the bias business students due show the second greatest change in their recorded vitals.
The experiment would have more successful data if it had a larger population as well as a more selective subject selection. The study would show more effective data if the entire subject group had anxiety or did not have anxiety instead of the mixed group that was used. The hypothesis should be adjusted for the experiment as well to be selective on what to consider. Instead of a hypothesis of a change in recorded vitals, it could focus on an increase in vitals. Looking at the specific Clarkson schools it may be found to be more beneficial to look at the majors within each school as an individual study. This information can allow for the disciplines and the majors to make possible adjustments or offer more assistance in managing stress during exam situations. College students are all required to take examinations and the preparedness of the student isn't the only factor affecting their test-taking abilities. Future development may lead to Clarkson having a reduction in the number of students with test anxiety and offer better management for stress for students.
Appendix
1. Pre-Questionnaire