Secondary Pupillary Response
What is it?
This demo shows that pupil dilation is due not only to changing light levels, but also to the subject being viewed.
How do you play?
Students are asked to cut out pictures from popular magazines which they find especially appealing and very disgusting. The teacher makes slides of these pictures. On the day of the demo, students are placed in dyads, one student facing the screen and the other opposite him. The lights are turned down and each of the students with their back to the screen is given a little flashlight. The teacher then begins to show the slides slowly. The student with the flashlight aims the light on the tip of the subject's nose. When the slides change the students pupils will change according to the change in light levels on the screen thus illustrating the primary pupillary response. The experimenter then waits for a couple of seconds and then tells the subjects whether his/her pupils got bigger or smaller in response to the topic of the slide being observed. This is known as the secondary pupillary response.
What can you achieve?
- You can illustrate both the primary response and the secondary response.
- It gives you a chance to explain that while the primary response is purely a result of the amount of light energy available, the secondary is purely a perceptual event.
- It gives the students a chance to have fun for a day.
What is included in the kit?
- 15 Small flashlights which run on two AA batteries (batteries not included)
- Complete instructions on how to construct the demo and run it
How much does it cost?
The kit costs $ 11. AA Batteries are available for 25¢ each.
