A New Way to Think About Developement

Reference: Advance for Speech Language Pathologists and Audiologists, (Sept.19, 2011)

Early motor experiences can shape infants' preferences for objects and faces, according to a new study.  The findings demonstrate that providing infants with "sticky mittens" to manipulate toys increases their interest in faces, suggesting advanced social development.

The study, conducted by Kennedy Krieger Institute, in Baltimore, MD, and Vanderbilt University, in Nashville, TN, supports a growing body of evidence that early motor development and self-produced motor experiences contribute to infants' understanding of the social world around them.  Conversely, this implies that delayed or impaired motor skills, such as in autism, could negatively impact social interactions and development. 

The results provide "a new way to think about typical and atypical development," said lead author Klaus Libertus, Phd, of the Center for Autism and Related Disorders at Kennedy Krieger.  "The mind is not independent from the body, especially during development.  As motor skills advance, other domains follow suit, indicating strong connections between seemingly unrelated domains.  Such connections have exciting implications, suggesting interventions could target the motor domain to foster social development."

Previous research found that infants with autism spectrum disorders (ASD) show less interest in faces and social orienting.  While the new study was conducted with typically developing infants, it indicates that infants at risk for ASD or showing signs of abnormal social development may benefit from motor training as early as 3 months of age.

"This means that early motor development is very important and parents should encourage motor experiences and active exploration by their child," said Dr. Libertus.  "Fostering motor development doesn't have to be complex.  Any interactions or games that encourage a child to develop independent motor skills are important."

Researchers divided 36 typically developing 3-month-olds into two groups.  One had active motor experiences, and the other had passive experiences.  Infants in the active group were given mittens affixed with strips of Velcro known as "sticky mittens".  A brief swipe of their arm made toys covered in Velcro stick, as if they had successfully grasped the object.  Parents demonstrated this by attaching a toy to the mitten.  The toy was removed, and the infant was encouraged to reach independently for the toy again.

Infants in the passive group were fitted with aesthetically similar mittens and toys that did not have Velcro.  They were only passive observers, as parents provided stimulation by moving a toy and touching it to the inside of the infant's palms.

After two weeks of daily training, the researchers tracked the infants' eye movements while they watched images of faces and toys flash on a computer screen.   Infants in the passive and active groups were compared with each other and to two control groups of untrained infants comprised of non-reaching 3-month-olds and independently reaching 5-month-olds.

The active group showed more interest in faces than objects, while the passive group showed no preference.  Infants in the active group focused on faces first, suggesting strengthening of a spontaneous preference.  Their social preferences were similar to those of the 5-month-olds, indicating advanced development following training.

Individual differences in the motor activity of all the 3-month-old infants were predictive of their spontaneous orienting to faces.   Regardless of experience, the more reaching attempts infants made, the stronger their tendency to look at faces.  Thus, motor experiences seem to drive social development.

"The most surprising result is a connection between early motor experiences and the emergence of orienting toward faces,"  said Dr. Libertus.  "Logically, one would predict the opposite.  But in the light of seeing actions as serving a social purpose, it makes sense."

A key question researchers hope to answer next is whether these early changes will translate into future gains for these children.

"Our results indicate a new direction for research on social development in infants," said Dr. Libertus.  He and his colleagues will continue to observe the children to see if the social development benefits achieved during the current study are sustained a year later.

Grants from the National Institutes of Health provided support for the study.

Reference
Libertus, K., Needham, A. (2011). Reaching experience increases face preference in 3-month-old infants. Developmental Science, online, Sept. 9.