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Bio 103, Lab 6, Oneself as a Biological Entity. II. Reacting
In last week's lab, we noticed that a part of oneself (the heart) was influenced by but not fully under the control of other parts of oneself. In this lab, we want to further develop the idea that oneself consists of an array of parts that interact with one another to give what we observe as behavior.
A touch starts signals moving in sensory neurons which eventually cause signals to move in motor neurons which eventually cause muscle contractions and movement. How long does it take to move when one is touched, and why? How much of that time is the time it takes for signals to move from the endings of sensory neurons to the endings of motor neurons? How much of that time is the time it takes muscles to contract and cause movement? That's what we'll be looking at in the first part of the lab, and studying further in the second part
Following the demonstration, you and your team should develop your own questions and observation protocols to explore some interesting aspect of what is going on in reacting. For example, would you expect the time taken to be different if the stimulus occurred at a more distant location on the body? On the same side as the response as opposed to the opposite side? If the response was with your dominant or your non-dominant hand? Would you expect the time to change if you were tired? preoccupied? had recently had coffee? Is it the time that signals take within the nervous system that changes or is it the time for muscles to contract and cause movement? Or both?
Don't try and answer ALL the questions. Pick one (or think up one) that you're interested in and have a guess about. And collect enough data so you have some confidence in your conclusions about that situation. And write up your question/hypothesis, observations, conclusions in the lab forum.
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Reaction Time (Claire and Valerie)
We did experiments with physiology equipment which measures reaction time. We took turns being the test subject and the tester. The tester would poke the subject in the dominant shoulder, and the subject, upon experiencing the stimulus, would press a button. We first measured our base responses. Latency is the time between stimulus and response.
Claire:
Test 1
Latency 1: 126 milliseconds
Latency 2: 40 milliseconds
Total: 166 milliseconds
Test 2
Latency 1: 139 milliseconds
Latency 2: 44 milliseconds
Total: 183 milliseconds
Valerie:
Test 1
Latency 1: 420 milliseconds
Latency 2: 37 milliseconds
Total: 457 milliseconds
Test 2
Latency 1: 128
Latency 2: 26
Total: 154
We thought that our times might change when we were distracted. First, the tester asked the subject questions while the subject was trying to respond to the stimulus (as well as the questions). We collected data for this, however, we believe that we collected the wrong data for this, so we will not include it.
Realizing our mistakes from the previous experiment, we tried a new one. The subject would watch a music video while simultaneously trying to respond to the stimulus.
Data from the Music Video experiment:
Valerie:
Latency 1: 107
Latency 2: 93
Total: 200
Latency 1: 380
Latency 2: 53
Total: 433
These are from the same experiment. In the latter instance, in the subject was distracted by an outside factor (people walked in the room).
Claire
Test 1:
Latency 1: 176
Latency 2: 23
Total: 199
Test 2:
Latency 1: 122
Latency 2: 26
Total: 148
We found that in some instances the distraction of the music video had more of an impact on the reaction time than others. For the most part, the music videos had very little effect on reaction time. What had more of an impact on our reaction time was outside distractions that we had not anticipated and couldn't control.
Therefore, we think that unanticipated distractions have the greatest effect on reaction time (with the music videos, we anticipated distraction).
By Claire and Valerie
Music, Teaxting, and our Reaction
For this lab we were experimenting our reaction to an outside force ("poking stick") and how this could be affected by another outside force (music and texting). Our hypothesis was that with increased outside forces the amount of reaction time would increase meaning it would take longer for us to react with comparison to our base. I (Paoli) would listen to music while Laura was texting. Our hypothesis was correct because while we were attempting to concentrate on the main outside force it was difficult to pay attention. For Laura it was more difficult since both of her outside forces dealt with her hand and her reaction was negatively influenced. Thus, the muscles were not given enough time to react and got confused in Lauras case since the sensory neurons were concentrating on two different forces. In my case, Laura would pause in between the outside force ("poking stick") I would get distracted with the music and forget that she was poking me! My muscles did not react at all at times since I was not concentrating and the sensory neurons were functioning towards the other outside force (music).
State of mind vs State of surroundings
INTRODUCTION
We wanted to observe factors that affect our reaction time to outside stimuli. What makes us react almost instantly to certain situations, relatively slowly to others, and almost not at all to others? Does reaction or reaction time depend on external factors such as.. level of noice/disturbance, potential distractions, intensity of stimulus, frequency of stimulus etc? Or are internal factors such as.. mental conditions, state of mind, drug-levels in our body (caffeine, nicotine etc) equally responsible?
OBSERVATIONS
Yashaswini's data:
Base
With music
On phone
Latency 1
9
51
18
Latency 2
41
67
66
Total Latency
50
118
84
Avg Latency 1:
94
Avg Latency 2:
99
Total Latency
193
On comparing Yashaswini's base trial with Michelle's, we notice that while Michelle's total latency was 193 ms, Yashaswini's was only 50ms! :O
This increased when Yashaswini was checking her voicemail to 84ms, which was still significantly lower (less than half!) than Michelle's base trial!
It also further increased when we played loud music. Total latency increased to more than double of that during the base trial, to 118ms.
CONCLUSION
We concluded that Yashaswini's response time was FREAKISHLY HIGH, during all the trials, ALL the time, she is probably in the state of mind where her defenses are up, and she is conscious of every tiny thing that could.. threaten/hurt her. This could be because of.. a high level of adrenaline in her blood. Or this could be as a result of a high amount of caffeine-intake. Either way, her responses were far quicker than Michelle's responses, that were closer to the class average that approxiamtely lay between 150-200ms.
However, even though Yashaswini's responses were really FAST compared to others, we did observe variations within her.. "unusual" range. Talking on phone was a distraction and her mind was occupied doing other things, such as.. dialing numbers, paying attention and responding to what the other person has to say etc. This is probably what slowed down reaction time.
Kristel Jesse & Sophie
Our group set out to find how different irritants on the lungs affect our reaction time. In order to measure this Sophie and Kristel each smoked a cigarette, and then measured their reaction times, and Jesse held his breath during the actual experiment.
BASE (average)
Latency 1 Latency 2 Total Latency
Jesse 144.2 36.4 180.6
Sophie 122.2 62 184.2
Kristel 104.4 29.8 134.2
EXPERIMENT (average SOPHIE AND KRISTEL SMOKE 1 CIGARETTE, JESSE HELD HIS BREATH)
Latency 1 Latency 2 Total Latency
Sophie 130.4 54.8 194.2
Kristel 100.6 34 134.6
Jesse 242.8 28.8 271.6
We noticed that for all of these irritants our average reaction time increased. However Kristel's reaction time only went up by .4, however Kristel's reactions had been extremely consistent throughout both the base and the experiment. Jesse's reaction may have been so extreme because the lung duress was tied directly to physical duress.
Latency Traces
Testing the Effects of Sight on Reaction Times
Kalyn & Karina
Hypothesis: How does the sight affect reaction rates? We predicted that using your sight will give you a faster reaction time because your body is anticipating the shock and therefore is primed to send the electrical signals to the brain.
T1 = Time to Muscle activity
T2 = Time to button press
T3 = Time from muscle activity to button press.
Touch knee with dominate hand while eyes are closed
Experiment #1
T1 = 0.255
T2 = 0.310
T3 = 0.055
Experiment #2
T1 = 0.251
T2 = 0.295
T3 = 0.044
Experiment #3
T1 = 0.304
T2 = 0.325
T3 = 0.021
Close Eyes
Experiment # 1
T1 = 0.242
T2 = 0.265
T3 = 0.023
Experiment #2
T1 = 0.216
T2 = 0.242
T3 = 0.026
Experiment #3
T1 = 0.198
T2 = 0.230
T3 = 0.032
Open Eyes – Look directly at experimenter
Experiment #1
T1 = 0.127
T2 = 0.273
T3 = 0.146
Experiment #2
T1 = 0.102
T2 = 0.268
T3 = 0.166
Experiment #3
T1 = 0.110
T2 = 0.265
T3 = 0.155
Conclusion: We found that the time from muscle activity to button press, our T3 results, showed faster response times when the participant’s eyes were closed rather than when they were open. We feel this is because using your sight creates more distractions for the body to process since it must account for multiple stimuli and the added shock. This makes opening your eyes result in a slower response time while closing the eyes primes the body for a response.
When your eyes are closed you can directly focus on the sensation and therefore the electrical signal of the shock can be relayed to the brain at a faster pace. Besides sight other factors could be taken into consideration which would also affect the reaction time of an individual. These factors include sobriety, fatigue, hunger and other things. Since factors vary greatly among individuals this would account for the large class differentiations result times found.
Relationship between Reaction Time and Distance
For our lab, we hypothesizes that the closer the point of contact is to your brain, the faster the reaction time is. We think that by having the point of contact closer to the brain, the exchange between the brain and the point of contact is shorter. The brain then relays the message to press the button to your hand much faster.
Methods: We decided to pick the arm and the foot as points of contact because the arm is closer to the brain and to the hand pressing the button and the foot is the furthest point from the brain.
We decided to test the arm first. We conducted three trials.
Trial 1
t1 = .179s
t2 = .252s
t3 = .073s
Trial 2
t1 = .16s
t2 = .355s
t3 = .195s
Trial 3
t1 = .106s
t2 = .174s
t3 = .068s
The average time from muscle activity to button press was .112s.
Then we tested the foot. We, again, conducted three trials.
Trial 1
t1 = .103s
t2 = .245s
t3 = .142s
Trial 2
t1 = .142s
t2 = .406s
t3 = .264s
Trial 3
t1 = .183s
t2 = .257s
t3 = .074s
The average time for t3 was: .16
Our hypothesis was proven incorrect. Our conclusion is that there is not a correlation between reaction time and distance. We expected that the reaction time for the arm would be faster that the reaction time for the foot. However, it is possible that this is due to human error. Also, we wonder if perhaps the position of our body would affect out reaction times. For example, maybe having your arm or foot in different positions would result in different reaction times. Another factor that may have affected our results is that Debbi was expecting the stimulus, so she might have pressed the button prematurely, which also would have affected the results.
-Debbi Chin and Herman Marcia
i have a better reaction time than stu - david
For this lab we focused on the question of whether or not the origin of a stimulus affected reaction time. After fixing electrodes to the participant's dominant thumb, we poked the participant in the calf, knee cap, and stomach. We recorded the time that elapsed between the poking stimulus and the button-pressing reaction, as well as the time between the poking stimulus and muscle action. Using these two values we were able to calculate the time elapsed between muscle action and the instant of button-pressing. Each participant was subjected to two trials (two calf, knee, and stomach pokes, respectively). We took the average time elapsed between (t1) poking stimulus and button-press, (t2) poking stimulus and muscle action, and (t3) muscle action and button-press.
Our results are as follows:
David:
Calf: t1=.1325 s, t2=.192 s, t3=.0595 s
Kneecap: t1=.149 s, t2=.214 s, t3=.065 s
Stomach: t1=.155 s, t2=.219 s, t3=.064 s
Julia
Calf: t1=.1775 s, t2=.2205 s, t3=.043 s
Kneecap: t1=.188 s, t2=.2395 s, t3=.0515 s
Stomach: t1=.174 s, t2=.214 s, t3=.040 s
We standardized stimulus on the same side (if the participant was right handed, we poked their right calf, their right knee cap, and the right side of their stomach) and we made sure the participant kept his/her eyes closed. This was meant to control for the variable of anticipation. The participant did not know when he/she was going to be poked and thus could not "prepare" for a more swift reaction.
Initially our hypothesis was that the distance between the origin of stimulus and the brain would increase the reaction time, but our data proved inconclusive on this point. On the whole, it was hard to isolate a trend between the two sets of data. One thing we did notice is that Julia's t3 (the time elapsed between muscle activity and button-press) was consistently lower than David's t3. We hypothesize that this is a result of David having a larger thumb muscle; because the muscle is composed of more cells the orchestration required to press the button would take longer.
Further testing would, of course, be necessary, due to the nature of experimenting on complex organisms such as humans.
Also, it is worth noting that Julia actually had the fastest reaction time recorded, with a t1 time of .098. Do not be fooled by our title.
Handedness and reaction times
We tested the variability of handedness. First we tested the standard (dominant hand, eyes closed, knee stimulous on the same side) for each of us (we are both right-handed). Then we tested handedness by doing 6 trials per person, 3 on each hand. We did the trials poking the same side as the button was in - but on our arms instead of our knees - and with our eyes open. Our results were as follows:
Standards:
Lili - t1 = .144, t2 = .166, t3 = .022
Halima - t1 = .142, t2 = .179, t3 = .037
Median reaction times:
Lili (left hand) - t1 = .075, t2 = .128, t3 = .053
Lili (right hand) - t1 = .086, t2 = .115, t3 = .029
Halima (left hand) - t1 = .049, t2 = .076, t3 = .027
Halima (right hand) - t1 = .046, t2 = .064, t3 = .018
First, we observed that the standard reaction times are higher for the stimulus to the muscle activity and the stimulus to the button press. We think that this can be attributed to the fact that, in the handedness trials, we were watching the stimulus be applied and the stimulus was located closer to the button press.
We found that our data showed a subtle trend that the time from muscle activity to button press was slightly longer for our left hands. We didn't notice any differences in the time from the stimulus to the muscle activity or the time from the stimulus to the button press, however. It would have been helpful to conduct more trials to see whether or not these are true trends.
-Terrible2s and Lili
Lab 6
In this lab we wanted to figure out whether our ability to see the stimulus affected the response time.
t1- time until muscle activity
t2- time until button is pressed
t3- t2 - t1 - time from muscle activity until button is pressed
Subject 1
Eyes closed
t1 = .111
t2 = .15
t3 = .039
Eyes Open
t1 = .048
t2 = .077
t3 = .029
Subject 2
Eyes Closed
t1 = 1.768
t2 = 1.83
t3 = .062
Eyes Open
t1 = .078
t2 = .122
t3 = .044
Subject 3
Eyes Closed
t1 = .097
t2 = .172
t3 = .075
Eyes Open
t1 = -.023
t2 = .049
t3 = .072
Conclusion
At the end of our experiment we realized that during the second trials, when our eyes were open, we had negative times. This was because when the person could see what was about to happen, there wasn't muscle activity, but the muscles were getting ready to move. Because of this the time between the stimulus and the time when the button was pressed was much shorter. We had predicted that this would happen, since being able to see what would happen, would mean that the person was anticipating, and would then react sooner, and maybe even prematurely.
The time between when there was any muscled activity and when the button was actually pressed was also much shorter during the second trials when our eyes were opened. We thought that this might mean that there was some sort of visual component. This would mean that somehow the message was related more quickly when it was done visually than when all we had to rely on was feeling the stimulus.
Maria, Mariah, Heather