Very little research to date has examined the first crucial months of preterm infants’ language development, but a new study out of our center sheds light on preterm babies’ earliest links between language and thought.
Let’s consider Holly and Salvador, two babies conceived on the same date. Both are due on September 1, but Holly surprises her parents by arriving exactly a month early. Although the two will always share the same maturational age (age since conception), Holly will have the opportunity to acquire an extra month of experience listening to language. For example, On January 1 Holly is four months old and Salvador is three months old. They’re the same maturational age, but Holly has had an additional month outside the womb hearing family and friends coo adoringly at her and sing “Twinkle Twinkle Little Star.”
On the one hand, you might suppose that if we test the two babies on a language development task that Holly will do better thanks to this extra experience. On the other hand, we know from pediatric evidence that healthy preterm infants tend to encounter language obstacles early in life that require intervention services. With this in mind, we might instead imagine that Holly will not perform as well as Salvador in a language-related task.
So does extra experience give healthy preterm infants like Holly a “boost?” Or do they lag behind their full-term counterparts? Or perhaps it’s neither option–once we adjust for maturational age, might preterm and full-term infants be on the same developmental trajectory? We decided to investigate these intriguing possibilities at our research center.
In previous work we found that between three and five months, full-term infants’ performance in a categorization task revealed their precocious ability to link language and thought. This time, we turned to pre-term infants and asked whether we’d find this same link and, if so, whether it might come earlier or later than full-term infants that are the same maturational age.
So how did the preterm infants do compared with their full-term counterparts? While we didn’t find any evidence of a “boost,” preterm infants exhibited the foundational link between language and thought on the same maturational timetable as full-term infants! When Holly is four months old and Salvador is three months old, their performance in the language task will look the same. This provides assurance that whatever obstacles preterm infants face in later language and cognitive development, these are unlikely to reflect difficulties in establishing a strong foundational link between language and core cognitive processes.