Needed for the Following Study:|
Modulation of Leg
Coordination Patterns in Infants with and without Down Syndrome
Rosa Angulo-Barroso, Ph.D.
Timothy R.B. Johnson, M.D.
Infants learn complex and adaptive forms of motor behavior as the information
generated by their own bodies (action) is dynamically coupled with the
information available in the context (perception). Infants must, therefore,
attend to relevant information for effective behavior to be selected.
classic conjugate reinforcement procedure, Rovee-Collier and her colleagues (Rovee-Collier
& Gekoski, 1979) have repeatedly shown that infants increase their leg
movement frequency to control a mobile when it is attached to their ankles.
However, this traditional experimental design allows multiple motor solutions to
the task (Collier, 1993) and therefore, it provides limited information about
the infants’ capacity to explore and select specific motor solutions. Although
infants with Down syndrome acquire new behaviors much slowly, they are complex
and adaptive organisms as well. Furthermore, the same learning principles that
take into account individual characteristics and task demands are applicable to
them. How infants discover task-specific patterns of coordination is the general
question addressed in this study. Specifically, I am interested in the process
by which infants solve motor problems in real time, that is, over the span of
minutes rather than weeks or months.
purpose of this study is two-fold:
to examine the motor activity profiles of infants with and with Down syndrome,
(2) to examine the exploratory strategies infants use to control their legs
when placed in a special reinforcement procedure.
To obtain the reinforcement - the movement of an overhead mobile - infants must
discover which pattern of leg movement is the one that triggers the mobile.
Infants will need to selectively attend to relevant sensory information and
explore their capacities, that is, engage in a perception-action process. To
solve the problem at hand, that of moving a mobile with a new or non-preferred
leg movement pattern, the stability of previously preferred movement patterns
will be temporarily lost and new forms of movement will become the preferred
ones. This study will provide useful information about the process by which
infants learn and remember how to solve motor problems. In addition, the
experimental procedure utilized in this study has some clinical intervention
potential. If indeed infants can select a specific pattern of movement to obtain
the reinforcement, then we can design intervention programs using this
experimental procedure so functional movements are reinforced and therefore
practiced. In addition, learning about the physical activity profiles of infants
with Down syndrome may provide useful information for early intervention in a
population that has a high incidence of adolescent and adulthood obesity.
This study is composed of 5 experiments:
a. To compare
and contrast the motor-perceptual learning capabilities of infants with and
without Down syndrome
Hypothesis 1a: Infants with DS will learn the contingent
relationship between leg movement and motion of the mobile 2 months later than
normally developing infants.
To compare and contrast the overall level of spontaneous movements in
infants with and
without Down syndrome.
The participants will be
normally developing infants and infants with Down syndrome from 3 to 7 months of
age. Infants enrolled in this study will come to the Motor development
laboratory for 1 to 5 45-minute sessions. Their participation will be voluntary
and contingent upon their parents’ consent. An effort will be made to have
equal distribution of gender, and inclusion of minorities in the study.
There is minimal risk involved in this study. Parents will remain close
to their infants at all times. The infant will be secure and save in the crib,
or in the infant seat. The electrical devices we utilized are grounded and
isolated. We have previously used these devices in other experiments without any
There is no guarantee that infants, parents or caregivers will directly
benefit from participating in this study. However, parents may learn more about
the perceptual-motor capacities of their infants, and new ways to stimulate
their physical activity.
will place infants in a supine or seated position with a view of an overhead
mobile or a TV screen. We will place small goniometers (Penny-Giles XM110 &
XM75) and EMG electrodes (Therapeutics Unlimited) on the surface of the
infant’s limbs. We will record the output signal from the goniometers (i.e.
angular displacement) and electrodes (i.e muscle activity) as the infant moves.
The goniometers, which will be interfaced with a computer and customized
software, will allow us to evaluate, in real-time, the characteristics of the
joint movement and therefore, to determine when the reinforcement (movement of
the mobile or picture in the screen) should be given. When the electrodes and
the goniometers are in place, we will videotape and collect data for no more
than 20 minutes. At the end of the session, we will weight and measure the
infant. In addition, we will place an actigraph (small watch-type device that
counts frequency of movements) on the infant’s ankle to be worn for 48hr.
There is an immense void in our knowledge about physical activity during infancy
as well as learning processes at this early age.
If we understand how infants learn and remember tasks like this one, we
will ultimately be able to improve the perceptual and motor development of
disabled infants. Also, better knowledge of the physical activity patterns of
infants with Down syndrome may help to better design interventions to ameliorate
the incidence of obesity in this population.
If you are interested in volunteering for this study,
please send an email to Rosa Angulo-Barroso at: firstname.lastname@example.org
or to Dale Ulrich at email@example.com or
call them at 734-936-2607.
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