Eye tracking based assessment of lexical processing and early lexical development in very preterm children

Associations between lexical processing and lexical development during the second year of life have been little studied in preterm children.

To evaluate associations between lexical processing at 18 months and lexical development between 12 and 18 months in very preterm children.

Correlational study.

25 Finnish-speaking children born <32 gestational weeks.

Lexical processing (reaction time RT; correct looking time CLT) was measured with an eye tracking technology-based task at 18 months' corrected age. Lexical development was measured longitudinally at 12-, 15- and 18-months' corrected age using the following screening instruments: the short form version of the MacArthur Communicative Development Inventories and the Communication and Symbolic Behavior Scale: Infant-Toddler Checklist.

The longer the RT of the child, the weaker expressive skills the child had at 12 and 15 months (correlations coefficient values -0.45 to -0.51). The more the child looked at the target image compared to the distractor (CLT), the stronger expressive skills the child had at 18 months (r = 0.45-0.52). A linear regression model with RT and gender as independent variables explained 33 % of the variance in lexical skills at 18 months. A model with CLT explained 40 % of expressive skills at 18 months.

Lexical processing at 18 months was associated with expressive lexical development in very preterm children. The results suggest eye tracking technology based methods may have utility in the assessment of early lexical growth in preterm children, although further research is needed to assess psychometric properties and predictive value of the method.