Science in Motion
Ursinus College
Teacher Notes
“Rewiring the Brain”
Learning and Brain Plasticity
Overview
In this lab, students throw beanbags at a target in a series of tests involving wearing and
not wearing special goggles that skew the vision about 15 degrees. The purpose of the lab
is to investigate how learning occurs and how the brain can adapt to changing conditions.
Time Needed to Complete Lab
The basic lab should take about one class period. The lab could easily fill two periods if
you allowed the students to follow up the basic lab by designing their own experiments
using the same equipment.
Target Grade Level
This lab could be used from 7th-12th grade depending on how you plan to use the lab.
This lab would be an excellent way to introduce the scientific method or in an
anatomy/physiology chapter.
Teacher Background
The capacity to learn is one of the most profound aspects of the human
nervous system. Despite our knowledge of the anatomy and related circuitry
or hard-wiring of the central nervous system (CNS), many neuroscientists
continue to search for the underlying basis of the brain’s ability to adapt
rapidly to new experiences. This adaptability, both conscious and
unconscious, is often termed neuronal plasticity and is considered to be
memory in the short-term and learning if remembered over the long-term.
Neuronal plasticity is demonstrated easily in this laboratory when a subject
wearing specially prepared goggles throws beanbags at a target. To
demonstrate the normal state, a subject first tosses beanbags, from a distance
of approximately 3 meters, directly at a target, such as a Post-it note, placed
on a wall 0.5 m above the floor. Next, the subject puts on prism goggles that
bend the light and throws at the target again. During this second trial, the
goggles should cause the wearer to throw the beanbags approximately 15
degrees off target. Subsequent trials wearing the goggles will create
an adaptive situation that influences motor performance that corrects for the
lenses’ shift and becomes part of the brain’s interpretation of what the eye is
seeing. As a result, if the subject performs a trial immediately after removing
the goggles, the beanbags should land approximately 15 degrees from the
target on the opposite side of the original displacement. Numerous regions of
the brain are involved in this visuomotor activity that incorporate the
necessary sensory information and control the motor output. As the student
throws the beanbags and identifies the target, reflected light from the target
enters the eye. The retina transduces this light into an appropriate signal for
the nervous system that is carried to multiple components of the visual
system. A visual perception of the target occurs. To move the muscles of the
arm to toss a beanbag at the target, the visual system signals the motor
system through cortical outflow directed toward the spinal cord. Here
appropriate motor neurons are activated to excite muscle fibers. Usually, the
student has the appropriate neural circuitry and hits the target on the first
trial. Of tremendous importance is the brain’s response to the shift of the
original visual signal due to the prism lenses that bend light and displace the
original visual input to a different location on the retina. See Figure 6. The
arm subsequently throws a beanbag to the original or wired location. Then
the visual system receives a new signal and a perception indicating that the
target has not been hit. With subsequent trials with the prism goggles, the
brain adapts and reconfigures this information. The new portion of the retina
is rewired to a new area in the cerebral cortex so that correct muscle groups
are activated to hit the target. The plasticity of the new response occurs
rapidly and is remembered, as shown by the response when the prism goggles
are removed. The previously learned correction factor is maintained in the
first few tries until the brain quickly corrects the action and returns to its
original state. While adaptation/plasticity is demonstrated easily in the
visuomotor activity, similar processes occur throughout the CNS and are
especially prevalent at the level of the cerebral cortex. Each sensory system,
in all likelihood, has an ability to adapt the sensory information that it
receives to changing events. More significantly, the extent of these
mechanisms in the human brain underlies our vast neural capabilities in
memory and learning that distinguish us from other species.
Preparation
Teachers will need to run off lab sheets. The lab file is three pages long. I recommend
inserting the graph page(a separate file) as page three and running off the 4 page lab as
two pages back to back.
Teachers will have to provide some background information to students. They should
cover the following topic before students begin the lab.
 Neurons and their role in the circuitry of the brain
 How the eye receives and interprets light stimuli
 That closely spaced grooves in glass or plastic can act as a prism and bend light
(a spoon in a glass of water can be used to demonstrate the bending of light – ask
students, “why it has that cut in half look?”)
NOTE: Students enjoy this lab and find it interesting and fun. It is easy for that fun to get
out of hand. It is highly recommended that teachers give clear boundaries before the lab
on what is acceptable behavior.
Answers to Questions
1. Visual pathways (eyes/retina, thalamus, visual cortex) cortical association
pathways(visual cortex to motor cortex) motor pathways(motor neurons to
muscles).
2. The first set of throws were the control to get a baseline of accuracy for the test
subject.
3. The thrower should have missed by about 15 degrees for the first throws and then
gradually gotten better as the brain adapted taking account for the glasses with a
correction factor.
4. When the goggles are removed the brain still uses the correction factor which will
cause the initial throws to be about 15 degrees to the opposite side of the target.
Gradually the thrower will relearn the correct location of the target. The speed of
this relearning will vary with the subject. In some subjects, where the last test
was delayed, they still remembered the correction factor for as long as three
hours.
5. Although the activity is “remembered” for only a short period of time, the
plasticity that is demonstrated is an important part of memory and learning.
6. Student answers will vary.
7. Student answers will vary.
Extensions and different approaches
Once students are done with this lab, they will probably have many questions. Do
different people doing the tosses get similar or different results? How does the time
between tests effect the results? What if right handed people used the left hand for the
test?
Student groups can plan experiments, collect data, and present their conclusions.
Adapted from the lab “Rewiring the Brain” by Bob Melton, Edmond Memorial High School, Edmond, OK
http://www.utsa.edu/tsi/assign/nlca/nlcapdf/07chp5.pdf