Dracula has lost
his pet bat and needs your help finding him! Help Dracula find
his bat by participating in the following activity.
Black cardboard paper cutout of a bat
Cardboard box lined with white cardboard paper
on the inside
Stare at the black bat for at least 30 seconds.
Immediately stare at the inside of the white
box.
What did you see when you started
staring at the white box? You should have seen a faint image
of the black bat that you were staring at. This faint image is
called an afterimage. The cause of the afterimage is thought
to be an adaptation of the sensory mechanism to a repeated or
uninterrupted stimulus. For example, strong odors that seem to
disappear after a while or how you don't notice the feel of your
clothes after you have been wearing them for a while. Your eyes
respond in similar ways.
The retina is located behind
your eye and contains light detecting cells.By staring at the
black bat you were stimulating some of these light detecting
cells more than others. These cells became fatigued and less
sensitive. This created an afterimage when you moved your eyes
to the white box. Now that you have the image of Dracula's bat
in your eyes, help Dracula search for his long lost friend. You
won't forget what his bat looks like for a while!
You can buy this resource on CD-ROM for
use on computers without internet access.
Visit our online
store for more information!
