Babies learn visual signals from experience

Babies learn to follow another person's gaze during infancy, and researchers have now found that exposure to visual experience outside the womb influences this critical ability more than maturational age.

"To the best of our knowledge, this is the first study showing that some aspects of the early development of social cognition is influenced by experience, even when the human brain is highly immature," said lead researcher Marcela Peña from Pontifical Catholic University of Chile in Chile.

Previous research on early cognitive development suggested that some cognitive functions develop only after the brain has matured sufficiently, while other cognitive functions develop in response to a rich social environment.

For the study, the researchers compared the gaze following abilities of premature and full term infants.

"Because preterm infants are exposed to face-to-face interactions earlier (in terms of postmenstrual age) than infants who are born at term, they may become sensitive to gaze direction sooner as well," the researchers explained.

A total of 81 healthy infants participated in the study and they were split into four groups: Full term 4-month-olds, full term 7-month-olds, preterm 7-month-olds, and preterm 10-month-olds.

The data showed that preterm 7-month-olds and preterm 10-month-olds behaved like full term 7-month-olds, looking to the toy on the side of the screen indicated by the woman's gaze.

Full term 4-month-olds, on the other hand, tended to look randomly to either side.

This pattern of results held even when the woman indicated direction with only her eyes, while her head continued to face forward.

The study appeared in the journal Psychological Science.