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Part 2 - Testing Subjects

  1. Identify 5 people (family and friends outside of class) who are not aware of this activity. Keep all subjects unaware of the upcoming experience.
  2. Test each subject individually. Ask them to sit down in a location that other subjects cannot observe. Rotate the headshot so that the image "stands on its head" (the eyes and mouth, however, will appear rightside-up).
  3. Show the upside-down headshot to your subject. Have them describe the whole image in terms of what they see. Ask: Is the person in this photo happy? Sad? Does anything appear strange about this image? Record their responses, noting whether they describe the face as upside-down or rightside-up.
  4. After the subject has commented on the headshot, rotate it to its upright position. Have the subject describe what they see and record their response.
  5. Repeat the activity with the same subject and discuss how the appearance of the person in the photo changes through the rotation. If there is a change, at what point does this occur?
    (At a certain point the image no longer appears to be a rightside-up person (with distorted facial features) that is undergoing major tilting. Our conception of it "jumps" to an upside-down image that tilts upwards, and the distortions are lost.)



  1. Why was it important to keep the subjects unaware of the activity?
    (You wanted to make sure that the initial response was not influenced by what they "expected" to see.)
  2. How many subjects did not observe the flipped-over features during their initial trial?
    (Most will have missed the inconsistencies in the image.)
  3. Once they were made aware of the effect, were the subjects still "tricked" by the image?
    (Answers will vary.)

The activities in this guide were contributed by Michael DiSpezio, a Massachusetts-based science writer and author of "Critical Thinking Puzzles" and "Awesome Experiments in Light & Sound" (Sterling Publishing Co., NY).

Academic Advisors for this Guide:

Corrine Lowen, Science Department, Wayland Public Schools, Wayland, MA
Suzanne Panico, Science Teacher Mentor, Cambridge Public Schools, Cambridge, MA
Anne E. Jones, Science Department, Wayland Middle School, Wayland, MA

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