Stimulus/Response Lesson Plan

Purpose:

In Stimulus and Response the students will


Observe the bones, joints, and muscles that move when the hand and foot respond.
Investigate the effect of practice on response time.
Investigate response time when the stimulus is nonvisual (auditory ad tactile)

Overview:

In Stimulus and Response the students work with a falling cup device to investigate response time. One student holds a cup poised to fall; another student places her dominant hand under the cup. When the responding student sees the cup start to fall, she pulls her hand our of the way. The students take turns responding to the falling cup, recording results in order to determine the minimum distance from which an object can be released and still allows the responding student to avoid being hit.
They then explore their hands and feet. Finally the students repeat a set of investigations after practicing and evaluate the effect practice has on response time.

Materials:

For each pair of students:
* 1 plastic cup with hole
* 1 lid for the cup with hole
* 1 dowel, 35 cm
* clothes pins (1 per pair)
* half sheet of paper
* 2 student lab sheets for Stimulus/Response data
* Response timer strips
 
For each team of students (4)
* 1 meter tape
 
For the class
* 1 pair of scissors
* transparent tape

Assembly of Falling Cup Device:

a. Snap a lid with hole on a cup with hole.
b. Slide a long dowle through the holes so that the cup with its lid can slide freely up and down.
c. Hold the stick in a vertical position on a desk top with the cup bottom side up.
d. Attach a clothes pin to the dowel above the cup to limit how high the cup can be raised above the desktop.

The Activity

1. Review Movement. Ask the students to review the systems in their bodies that come into play when they move. (Skeleton, joints, muscles) When all of these systems work together to provide movement, it is called coordination.

2. Introduce Stimulus. Tell students that coordinated movements of the human body don't happen by themselves. Movements are directed by the central nervous system - the brain, spinal column, and nerves. The central nervous system gets information from the outside through special systems called senses. (sight, sound, touch, taste, and smell).

When sensory input triggers an action, that input is a stimulus. Discuss different kinds of stimuli.

3. Demonstrate the falling cup. Bring out the falling cup device with the clothes pin at the top of the dowel. Place it on a desktop in ready position. Tell the students to imagine that the cup is filled with cement and likely to slide down the dowel at any moment. Release the cup and show how quickly it can fall to the desktop.

Ask for a volunteer to place a hand on the desktop right next to the dowel. Stress that the responding student's fingers must be touching the dowel. Ask the class, "Do you think she will be able to get her hand out of the way when she sees the cup fall?"

Tell the volunteer to pull her hand away when she sees the cup begin to fall. Release the cup and let the student respond. In all likelihood, she will withdraw her hand before being hit.

4. Introduce Response. Reinforce that the sight of the cup falling was the stimulus that started the student moving. Explain that the action of pulling a hand out of the way is the reponse.

5. Begin the Falling Cup Investigation

a. Allow time for Free exploration of materials.
 
b. Discuss refining the release. Have all students measure where they start their clothes pin so they can always start from the same position. You may also tape a half sheet of paper to the cup to shield the release of the cup.
 
c. Establish a Standard Release Height-Ask team members to ask 1 minute to discuss at what height the cup should be set so that it is a challenge to get their hand out of the way consistently. Then poll the groups. Write their suggested heights on the board and average them. Use the average as the standard release height for further investigations.
 
d. Introduce the student sheet. It is time to gather data comparing the response of their left and right hands.
 
e. Describe data recording. After the students have filled in their names and the date, give the following instructions.

The stimulus (vision) and the response (right hand) have been filled in for the first data box. Fill in the height of the drop. In this case the standard release height you established should be recorded.

One person is the cup releaser; the other is the responder.

Each time the reponder's hand is hit, an X is recorded in the hit column; misses are recorded in the miss column.

Allow students to conduct the investigation. They may record other response times after completing the student sheet. (feet, left hand etc.)

6. Review the Results

Which body part responds quickest to the falling cup? (HAND)

Which is slowest? (FOOT)

Why might that be the case? (DISTANCE FOR THE BRAIN AND SPINAL CORD)

Is there anything you can do to improve your response time? (PRACTICE AND CONCENTRATE)

7. Challenge: Record your data for the experiment on your Vital Signs Spreadsheet. Make sure all members on the team are included. Compare your answers to those of students from other geographical locations. Are there any marked differences or similarities? If so, can you give an explanation for them? How might this result from this lab experiment differ from "Gotta Have a Heart" "Lung Capacity" with regards to other populations? Report your results and comments at the next lab session.

Stimulus/Response Lab Sheet