Name_____________________________
Bilateral Transfer
Objective: Demonstrate motor control phenomenon known as bilateral transfer. It is observed
when a on-practiced limb shows a performance increase from a motor skill as a result of
practicing the skill with the opposite limb.
Goal of the activity: is to move through the pathway as quickly as possible but with as few errors
as possible. The subject should be told this goal and both the amount of time to trace the pattern
and the number of errors made will be calculated into the score for each trial.
Equipment: five different colored pencils, paper, tape, mirror, stop watch, screen, a copy of star
target
Activity: The mirror is positioned so the performer can see his or her own hand and the
pathway by looking into the mirror. The hand is covered so that the person cannot see it and
must rely on mirror in order to complete the tracing of the object. The timer must measure the
tracing time to the nearest tenth of a second. The timer must say “STOP” when the subject has
completed the outlining of the target. Time begins when the pencil moves and ends when the
lines have been joined at the finish mark. The subject should be told that both the amount of
time to trace the pattern and the number of errors made will be calculated into the score for each
trial.
Begin at the lower right point for the right hand or the lower left point for the left hand.
When the subject is ready, say “GO” at which time the subject should begin moving the pencil or
stylus in a counter-clockwise direction for the right hand or a clockwise direction for the left hand.
(These different directions of movement for right and left handed subjects keep the hand from
blocking sight of the upcoming pathway to be traced). When an error is made, subjects should be
instructed to return to the pathway as close to the lace where he/she left the pathway. An error
is: a pencil mark that can be observed outside the pathway border. Record time and errors for
each performance below.
Individual Performance Scoring Table
Hand
Trial
Non-preferred
1
Preferred
2
Preferred
3
Non-Preferred
4
Time (sec)
Errors
Score
Calculate your score for each trial by using the following formula: Score=100 X seconds +
errors
1. Using the above recorded individual scores, Calculate and record on the group data chart
below each subject’s results.
Subject
1NP
2P
3P
4NP
MEAN SCORE
P
NP
TOT
1
2
3
TOTALS
Group Data Chart:
2. From the group data sheet calculate the mean (MEAN = SUM(X)  N) of the four trials for
your lab group. Draw a line graph to illustrate these means, where Score is on the Y Axis
and Trials is on the X Axis. On the graph indicate performance for the non-preferred hand
(Trials 1 and 4) with an X and for the preferred hand (Trials 2-3) with an 0. Use the
attached graph.
3.
Calculate the % of improvement for the non-preferred hand by:
% Improvement = (Trial 3 score - Trial 1score)  Trial 3 score
% Improvement = ____________%
4. What evidence resulted from this lab that demonstrates that bilateral transfer occurs?
5. What are two reasons that explain why the bilateral transfer demonstrated in this lab
occurred?
6. Describe a motor skill situation you are familiar with in which you could take advantage of the
bilateral transfer phenomenon to help a person learn a new skill for which performing with
either hand or leg is important to becoming a skilled person.