This activity page will offer:

• Insight into the physiological effects of stress
• Construction of an electronic temperature measuring device
• Investigation into the effect of emotion on body temperature
• Investigation into the effect of relaxation on body temperature

Temperature Control
A thermistor is an electronic device whose resistance varies with temperature. When connected to a multimeter that is set to measure resistance, the thermistor can be used to indicate relative temperatures. In this activity, you'll attach a thermistor to your fingertip and uncover a baseline temperature. Then, you'll observe how acting out various emotional states affects this baseline. Finally, you'll investigate if relaxation techniques can produce changes in the detected temperature.

Materials

• Thermistor (available through electronics stores such as Radio Shack)
• Connecting wires with alligator clips
• Tape
• Multimeter (also referred to as a voltmeter, these are basic electronic boxes that can measure voltage, current, and resistance (hence the "multi" in their name.) These are also available at an electronics store.

Steps

1. Work with a partner. One of you will read measurements while the other will have the thermistor attached to his/her finger. Wrap the thermistor in a piece of tape so that hard and/or sharp edges are covered.
2. Use alligator clip connectors to attach each lead from your thermistor to one of the probes of your multimeter. 3. Set the multimeter to detect and measure resistance. Set aside for several moments until the readout becomes stable. Record this value as room temperature resistance. Gently blow on the thermistor. How does your hot breath affect the displayed resistance?
3. Position the wrapped thermistor against the inside of the tip of the index finger. Use another piece of tape to secure the wrapped thermistor to the skin. CAUTION: Do not tightly bind the tape since this would interfere with blood circulation. Wait until the display becomes stable. Record this value as baseline resistance.
4. For several moments, have the subject act out the emotion of anger. Observe and record any changes in the detected resistance.
5. Then, have the subject act out the emotional states of sadness, fright, happiness, and content. Each time, record any observed changes in the resistance.
6. Once again, obtain a baseline measurement for temperature.
7. Then, have the subject enter a less-stressed state. Encourage them to relax their muscles and meditate on calming thoughts. Suggest deep breathing and concentrate on the word "calm." Maintain this state for several minutes. Note and record any changes in temperature.
8. Exchange roles and repeat steps 3 through 7.
   

Questions

1. How does heat affect the thermistor?
   
2. Did mood role playing affect the resistance?
   
3. How did relaxation affect the multimeter display?
   

Heated Extension
In this activity you examined temperature changes in fingertips. Yet, the monks appeared to increase the temperature of their shoulders and back. How would you adapt this classroom activity to more accurately test the monks' ability to significantly alter body temperature?

Film Fakery
Was the clip that showed monks steam-drying wet towels faked? How do you know? What proof (if any) do you have that validates this video footage? Should we believe someone just because they are a scientist? Consider lunar landings. Some people say that the footage showing astronauts on the moon is faked. How do we know that these images are real and not a product of some Hollywood special effects team? How might increasing ability of digital fakery affect our future trust in the media?

Biofeedback on the Airwaves
Write a 5-minute infomercial in which you try to convince your listener audience to pursue biofeedback therapies. Make sure to address their apprehension and inertia in moving to a new healing strategy. Cite the appropriate resources. You might even "stage" an interview with a fictitious researcher, physician or satisfied patient. With your instructor's approval, perform a staged reading of your work or videotape it for class showing at a later date.

More FX
In this activity, you observed the effects of mood role-playing and relaxation technique on the ability to regulate body temperature. Consider additional parameters such as breathing rate, relative percent of exhaled carbon dioxide, pulse rate, and blood pressure. Expand your experimental design to include any of the additional parameters. Share your design with your instructor and with his or her permission perform the activity.

GSR
The acronym GSR stands for galvanic skin response. GSR is a measurement of the skin's electrical conductivity. When you perspire, the skin's ability to conduct electrical current increases. By measuring this change in conductivity, scientists can gague emotional response. Use Internet and print resources to uncover how the GSR is used as a measurement in lie-detecting devices.

Web Connection
BIOFEEDBACK: Review, History and Application http://members.cts.com/crash/d/deohair/psychoph.html
A history of biofeedback and its use and acceptance as a therapeutic tool

Biofeedback and Hypertension
http://www.nau.edu/~eaw/future.htm
An example of how biofeedback may be used in the treatment of hypertension

Mind, Body, Medicine
http://www.emory.edu/ACAD_EXCHANGE/2002/
febmar/raisonqa.html
A scientist's speculation and inquiry perspective on temperature regulation by monks

Academic Advisors for this Guide:
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools, Cambridge, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA
Gary Pinkall, Middle School Science Teacher, Great Bend Public Schools, Great Bend, KS