Question

Brain/Nerve Stimuli and Conduction Speed Test - Lab

Problem: How do we respond to auditory, visual, and physical stimuli?

Hypothesis: Which type of stimulus will you respond to the fastest? Why?
Physical because the signal travels faster


Materials: Ruler, Partner.

Procedures: Run each test for each member of your group, with each hand.

Visual Test
1. Subject one dangles their dominant hand off the edge of a table.
2. Subject two holds a 30 centimeter (12-inch) ruler between two fingers at the 30 cm mark, having the 0 mark touching the subject one’s index finger.
3. Subject two tells subject one to grab the ruler as fast as possible, when they SEE it being released.
4. Record the centimeter measurement.
5. Repeat this three times, for a total of four measurements. Then repeat for your non-dominant hand.

Auditory Test
1. Subject one is blindfolded before dangling their dominant hand off the edge of a table.
2. Subject two holds a 30 centimeter (12-inch) ruler between two fingers at the 30 cm mark, having the 0 mark touching the subject one’s index finger.
3. Subject two tells subject one to grab the ruler as fast as possible, when they HEAR the word “release” being said.
4. Subject two simultaneously says “release” and lets go of the ruler. Record the centimeter measurement.
5. Repeat this three times, for a total of four measurements. Then repeat for your non-dominant hand.

Tactile Test
1. Subject one is blindfolded before dangling their dominant hand off the edge of a table.
2. Subject two holds a 30 centimeter (12-inch) ruler between two fingers at the 30 cm mark, having the 0 mark touching the subject one’s index finger.
3. Subject two tells subject one to grab the ruler as fast as possible, when they FEEL their non-dominant shoulder being touched.
4. Subject two simultaneously touches the shoulder and lets go of the ruler. Record the centimeter measurement.
5. Repeat this three times, for a total of four measurements. Then repeat for your non-dominant hand.



Vision Test - Data in cm’s

Test
Dom Hand
Non-Dom
1
8
9
2
13
14
3
12
7
4
15
10
Avg
12
10


Auditory Test - Data in cm’s

Test
Dom Hand
Non-Dom
1
20
8
2
14
5
3
9
2
4
25
9
Avg
17
6




Tactile Test - Data in cm’s

Test
Dom Hand
Non-Dom
1
4
12
2
19
4
3
3
9
4
8
4
Avg
8.5
7.25




Average Reaction Time:

Test
Dom Hand avg CM Dist
Dom Hand avg reaction time in (s)
Non-Dom Hand avg CM Dist
Non-Dom Hand avg reaction time in (s)
Visual
12
.16
10
.14
Auditory
17
.19
6
.11
Tactile
8.5
.13
7.25
.13



Create a Test:
Create a test using similar materials that expands on what we just completed in class. List the item or you are testing, the procedures and data you’d like to gather.

Play music, have the subject hold a timer, start the timer at the same time music starts, stop the music while the subject also has to stop the timer as soon as possible.


Data for your Test Creation:

How fast your reaction is.



Post-Lab Questions

1. What problems did you encounter during the lab? Any bias or chance that your data is inaccurate? Why or why not?
No, there were no problems.


2. Analyze your data vs. your hypothesis, giving information about your success or failure with each type of stimuli? Was your hypothesis correct? Why or why not? (5+ Sentences)




3. How might you use the information you have received from this lab? Apply this test into your real world living and gathering of information.




4. What other things that we have discussed might affect the outcome of this lab?




5. What other questions do you have about how we process information and stimuli we receive?





short sentences

Answer 1

1. Problems and bias
- Small sample size.
- Human timing error when releasing the ruler.
- Anticipation by the subject changed some trials.
- Blindfolds or hearing differences may not have been perfect.
- These factors can make some data inaccurate.

2. Data vs. hypothesis
- My hypothesis said physical (tactile) would be fastest.
- For the dominant hand tactile was the fastest (.13 s).
- For the non-dominant hand auditory was fastest (.11 s).
- Overall tactile had the lowest average (.13 s) compared to visual and auditory (.15 s).
- The hypothesis is mostly supported, but results vary by hand and show inconsistency.
- Measurement method and human error reduce confidence in a firm conclusion.

3. Real-world uses
- Use tactile alarms for very fast, local reactions.
- Use auditory or visual signals for distance or group alerts.
- Apply this in sports and driving training.
- Design safety systems based on fastest effective cue.
- Teach people to avoid anticipation and practice quick, accurate responses.

4. Other affecting factors
- Fatigue and attention.
- Practice and anticipation.
- Hand dominance and coordination.
- Sensory ability (hearing or vision).
- Temperature and nerve conduction speed.
- Measurement error and reaction type (simple vs. choice).

5. Other questions
- How does the brain combine signals from different senses?
- How much does age change reaction time?
- How does myelination affect conduction speed?
- How much can training improve reaction time?
- Are startle reflexes faster than voluntary reactions?
- How do stimulus intensity and predictability change results?