Brain, Interrupted: Premature Babies Show Lack Of Interest In Others, A Trait Linked To Autism
Premature babies who are born before 37 weeks tend to face many complications during their first year of life. Some problems, like breathing issues, are apparent at birth, while others like developmental delays can appear later in life. Now, a recent study published in the journal Infancy found preemies with atypical social communication may be more susceptible to autism.
Because of the extent to which they are treated medically, premature infants with health complications are more likely to come in contact with a number of people during their first days than are babies born on schedule. These procedures alone are estimated to limit the amount of social and physical contact a premature infant has with its mother to 14 percent. This less than ideal quality of communication could cause premature infants to develop atypical social communication skills, therefore, raising the risk for autism.
“Preterm infants get a tremendous amount of stress in the early days of birth, because the environment is profoundly different from that of the womb," said Masahiro Imafuku, lead author of the study from Kyoto University in Japan, in the press release.
He added: "This makes them much more prone to developmental difficulties, even if they seem perfectly fine when they leave the hospital."
Imafuku and his colleagues sought to observe the gaze behavior of low-risk preterm and full-term infants at 6 and 12 months in two types of eye-tracking tasks.
In the first part of the study, the researchers simultaneously displayed videos showing people and geometric patterns to these infants to see which videos they preferred. The study focused on gaze because it signifies interest, meaning the longer time spent looking at the people in the video, the more interest the baby has in others. The researchers found full-term infants spent more time looking at the people video, while a significant number of preterm babies showed more interest in the geometric motion.
Later, the infants were examined to see how well they could follow the gaze of others. This exercise signifies an understanding of other’s intention and the ability to perceive and comprehend language, as well as produce and use words and sentences for social communication. Similar to the first experiment, 6-month-old full-term infants followed the gazes of people in the video, whereas preterm infants had difficulty doing so.
Despite these results, the researchers emphasize preterm infants do end up developing interest in other people and follow eye directions. However, the differences between when this occurs for full-term infants and preterm infants suggests their nervous systems develop differently during the first year of life.
One study found the reason why preterm babies cry with a shrill, high pitch is linked to the vagus nerve — the longest cranial nerve that contains motor and sensory fibers, passing through the neck and thorax to the abdomen. The vagus nerve has low activity in preterm infants compared to full-term babies. The distinct shrill reflects the activity of the nerve, which is related to the regulation of heart and throat function, health, and cognitive abilities. Researchers are still curious whether the shrill cries are linked to abnormal cognitive development in preemies.
In regards to social development, premature babies have been found to experience more problems in school and in childhood socializing than full-term babies. In a 2000 study, researchers observed the development of babies who were born prematurely with those delivered after a full- term birth until the age of 10. Children born prematurely had more behavioral, learning, and thinking problems than those born full-term. They measured poorly on social skills and were more prone to peer conflict, having fewer friends and less social success.
Preterm birth is continually rising with about 380,000 babies born too soon each year in the U.S. These studies have implications for how parents of preemies choose to engage with their children and how to encourage them to engage with others. Parents should make a special effort to enrich the social and cognitive development of their children with promoting more physical contact, bright objects, and social integration with others.
Source: Imafuku M, Kawai M, Niwa F et al. Preference for Dynamic Human Images and Gaze-Following Abilities in Preterm Infants at 6 and 12 Months of Age: An Eye-Tracking Study. Infancy. 2016.