Statistical Learning Among Preschoolers With and Without Developmental Language Disorder: Examining Effects of Language Status, Age, and Prior Learning.

Purpose: Our goal was to compare statistical learning abilities between preschoolers with developmental language disorder (DLD) and peers with typical development (TD) by assessing their learning of two artificial grammars.

Method: Four- and 5-year-olds with and without DLD were compared on their statistical learning ability using two artificial grammars. After learning an aX grammar, participants learned a relatively more complex abX grammar with a nonadjacent relationship between a and X. Participants were tested on their generalization of the grammatical pattern to new sequences with novel X elements that conformed to (aX, abX) or violated (Xa, baX) the grammars.

Results: Results revealed an interaction between age and language group. Four-year-olds with and without DLD performed equivalently on the aX and abX grammar tests, and neither of the 4-year-old groups' accuracy scores exceeded chance. In contrast, among 5-year-olds, TD participants scored significantly higher on aX tests compared to participants with DLD, but the groups' abX scores did not differ. Five-year-old participants with DLD did not exceed chance on any test, whereas 5-year-old TD participants' scores exceeded chance on all grammar learning outcomes. Regression analyses indicated that aX performance positively predicted learning outcomes on the subsequent abX grammar for TD participants.

Conclusion: These results indicate that preschool-age participants with DLD show deficits relative to typical peers in statistical learning, but group differences vary with participant age and type of grammatical structure being tested.

Supplemental material: https://doi.org/10.23641/asha.26487376.