Around 50 percent of children born preterm seem to have some sort of disability or disorder. Language disorders seem to be more common around preterm children and it deeply affects their life. Preterm toddlers tend to score lower on standardized tests compared to their full-term peers, and their vocabulary growth tends to be at a slower rate too (Marchman, Adams, Loi, Fernald, & Feldman, 2016). Finding the causes and consequences of the preterm and full-term individuals is important because of early identification. There are many factors for language delays and identifying these factors is highly important. Recognizing these factors can help find which preterm children are more at risk on developing a learning disability.
Marchman et al. wanted to find if early language processing in preterm children predicted later receptive vocabulary knowledge (2016). To test this, the researchers used a prospective longitudinal design with 30 preterm children (15 girls and 15 boys) with a gestation age (GA) less than 32 weeks and birth weight (BW) of less than 1800 grams. Families were found through neonatal intensive care units, through research registries, and online newsletters. Some of these families were excluded due to medical conditions that could’ve affected the results.
Marchman et al. tested preterm children on their vocabulary size, receptive and expressive language, real-time language comprehension, and receptive vocabulary at 36 months (2016). Vocabulary size was measured through the MacArthur-Bates CDI: Words and Gestures. The children were tested by their parents and had to mark the words that the child understood and repeated. For receptive and expressive language, the researchers tested the children at 18 months by using the Bayley Scales of Infant and Toddler Development (BSID-III). For this assessment children had to “point to a named picture, follow simple and complex commands, and produce words” (Marchman et al., 2016). Real-time language comprehension was determined by evaluating children at 18 months by using the looking-while-listening (LWL) procedure. The children saw a pair of images with objects that appeared on a screen with a voice record. The LWL procedure only lasted about five minutes and children were tested twice. To measure the children’s receptive vocabulary, researchers used the Peabody Picture Vocabulary Test, fourth edition (PPVT-4). For this test, researchers showed four colored pictures, and children had to choose which picture best represented the word that was mentioned by the examiner.