[EDLING:1101] When It Comes to Babies Learning Language, the Eyes Have It

[Francis M Hult]

When It Comes to Babies Learning Language, the Eyes Have It

http://www.newswise.com/p/articles/view/515993/

University of Washington 

Wed 09-Nov-2005, 01:00 ET

Newswise - Infants begin pulling off an amazing feat sometime in the final three months of 
their first year of life. They learn an important social interaction by following the gaze 
of an adult, a step that scientists believe gives babies a leg up on understanding 
language. 

University of Washington psychologists Rechele Brooks and Andrew Meltzoff have pinpointed 
this developmental step as beginning somewhere in the 10th or 11th month of life, and have 
found that infants who are advanced in gaze-following behavior before their first birthday 
understand nearly twice as many words when they are 18 months old.

Writing in the current issue of the journal Developmental Science, Brooks and Meltzoff 
provide further evidence for the importance of eyes in human social interactions and trace 
how gaze-following develops in infants. Three years ago they reported that 12- 14- and 
18-month-old infants are much more likely to look at an object when a person turns toward 
it with open eyes rather than closed eyes.

"Our work shows that babies can look where an adult is looking but that it isn't easy, 
particularly at home where there are a lot of distractions," said Brooks, who is a 
research associate at the UW's Institute for Learning and Brain Sciences. 

"We have found that at 9 months babies are beginning to do this by following the movement 
of the head. At 10 and 11 months they are following the head and the eyes. The eyes add 
important information and the babies are more consistently following the head when the 
eyes are open. It is as if a light is going off in their head. This is a clear shift and 
an important advance."

Brooks and Meltzoff refer to the behavior of a baby (or an adult) looking where another 
has just looked as "gaze-following." Psychologist have known for some time that among 
adults detecting the direction of another's glance is a crucial component of human social 
interaction.

"This line of research is important because following another person's line of sight is 
crucial for understanding the emotions of other people and, as we are now showing, 
learning about language," said Meltzoff, who is co-director of the institute and a 
professor of psychology.

The new study is part of an effort by UW researchers to understand the development of 
gaze-following in babies. To do this, they tested 96 normally developing infants. There 
were 32 infants at each of three ages, 9, 10 and 11 months. Equal numbers of boys and 
girls in each age group were randomly assigned to eyes open or shut conditions.

Each infant was seated in a parent's lap, across a small table from a researcher. Parents 
were instructed not to move their head or talk during the experiment. The researcher 
played with an infant before placing two identical toys on pedestals to the left and right 
of the table. Then the researcher resumed playing with the child before starting four 
head-turning trials. In the trials the researcher made eye contact with the infant before 
silently turning her head toward either the toy on the left or the one on the right. In 
the eyes-open condition, the researcher kept her eyes open and turned her head from the 
child to one of the toys for about seven seconds before turning back to the child. The 
procedure was the same in the eye-closed trials, except the researcher shut her eyes 
before turning toward one of the toys and didn't open them again until she was facing the 
infant.

In a follow-up interview when the infants were 18 months old, parents were asked to check 
off on a list how many words their child understood.

There were marked differences in the babies' ability to gaze-follow based on age. The 
9-month-olds turned their heads toward a toy nearly as often in the closed-eyes condition 
as in the open-eyes conditions. However, the 10- and 11-month-olds looked at a toy 
significantly more often when the researchers turned with her eyes open than when she 
turned with her eyes closed.

About one-third of the infants in the open-eyes condition also made simultaneous sounds 
such as "ah" or "hmm" when they engaged in gaze-following. Babies at this age are unable 
to speak but can make very simple sounds. Typically developing babies experience a burst 
of language between 18 and 24 months of age. 

In this study, the babies who simultaneously followed the eyes of the researcher and made 
vocalizations when they were 10 or 11 months old understood an average of 337 words at 18 
months old while the other babies understood an average of 195 words.

"The sounds they are making are very simple, but some children are looking and making 
these sounds spontaneously," said Brooks. "They are creating a social interaction or a 
link. There seems to be something special about the vocalization when they are looking at 
the toy. They are using social information to pick out what we are focusing on. They can't 
vocalize words, but they are carefully watching where we are looking. We think they are 
using social information and getting a boost in figuring out the social and language world 
together."

"Although the babies are too young to talk to us, those individual babies who are most 
attuned to our eye gaze are the same babies who pick up language faster more than half a 
year later," said Meltzoff. "This is a fascinating connection between the social and 
linguistic world and suggests that language acquisition is supported by preverbal social 
interaction.

"To do this a baby has an important social regularity to master: follow mom's eyes and you 
can discover what she is talking about. This study shows that babies first master this 
social information between 10 and 11 months of age, and it may be no coincidence that 
there is a language explosion soon thereafter. It is as if babies have broken the code of 
what mom is talking about and words begin pouring out of the baby to the parents' 
delight," he said.

The UW researchers are following the same group of babies to see if gaze-following and 
vocalization at an early age predict increased language understanding and use at 24 and 30 
months of age.

The National Institute of Child Health and Human Development, the Tamaki Foundation, the 
Virginia Merrill Bloedel Hearing Research Center, the Talaris Research Institute and the 
Apex Foundation, the family foundation of Bruce and Jolene McCaw, supported the research.