IG+Lab+-+Reflexes+and+reaction+times

Reflexes and reaction times
Reflexes and reactions can described in standard sequence of events:

An example of this could be the response to touching a hot object:

Carry out follow each of the procedures for each one describe it as above (add your examples to your notes)
 * Your task**


 * Pupil dilation/reflex**
 * 1) Ask your partner to close his/her eyes
 * 2) Wait for approximately 1 minute
 * 3) Ask your partner to open their eyes and at the same time shine the edge of a flashlight/torch beam into their eyes
 * 4) Observe what happens to the size of their pupil

//Safety concerns: shining very bright lights into peoples eyes can harm them. Make sure the light you use is not a strong one and only use the edge of the beam for a few seconds.//


 * Patella reflex**
 * 1) Ask your partner to sit on a surface of chair high enough that their feet cannot touch the ground.
 * 2) Use your hand to locate the bottom of the patella (knee cap)
 * 3) With the side of your flattened hand (palm facing upwards) strike their leg just below the patella.

//Safety concerns: strikes to the knee should be done gently. Avoid using enough force to hurt yourself or your partner.//


 * Ruler drop 1**

Equipment:
 * metre rule

Method:
 * 1) Hold the rule near the end and let it hang down.
 * 2) Have your partner put his or her hand at the bottom of the ruler (just below the end, fingers at leat 2cm apart) and have them ready to grab the rule.
 * 3) Tell your partner that you will drop the ruler sometime within the next 5 seconds and that they are supposed to catch the ruler as fast as they can after it is dropped.
 * 4) Record the level at which they catch the ruler (you can convert the distance into reaction time with the table below).
 * 5) Test the same person 3 to 5 times (vary the time of dropping the ruler within the 5 second "drop-zone" so the other person cannot guess when you will drop the ruler).


 * Distance (mm) || Time (ms) ||
 * 50 || 100 ||
 * 100 || 140 ||
 * 150 || 170 ||
 * 200 || 200 ||
 * 255 || 230 ||
 * 305 || 250 ||
 * 430 || 300 ||
 * 610 || 350 ||
 * 790 || 400 ||
 * 990 || 450 ||


 * Ruler drop 2**

Equipment:
 * metre rule

Method:


 * 1) Hold the rule near the end and let it hang down.
 * 2) Have your partner put his or her hand at the bottom of the ruler (just below the end, fingers at leat 2cm apart) and have them ready to grab the rule.
 * 3) Ask your partner to touch the tips of their fingers of their second hand (hand open) to the ruler half way up (this is how they will sense when the rule drops).
 * 4) Ask your partner to close their eyes.
 * 5) Tell your partner that you will drop the ruler sometime within the next 5 seconds and that they are supposed to catch the ruler as fast as they can after it is dropped using their bottom hand only.
 * 6) Record the level at which they catch the ruler (you can convert the distance into reaction time with the table above).
 * 7) Test the same person 3 to 5 times (vary the time of dropping the ruler within the 5 second "drop-zone" so the other person cannot guess when you will drop the ruler).


 * Extension: compare the reaction times of the two rule drops.**
 * 1) Do your results compare with other groups? Describe similarities and differences you find.
 * 2) Suggest reasons for the differences between the two sets of reaction times.