Statistical learning in language disorder (Kapa & Mettler, 2024)

<b>Purpose: </b>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.<b>Method: </b>Four- and 5-year-olds with and without DLD were compared on their statistical learning ability using two artificial grammars. After learning an <i>aX</i> grammar, participants learned a relatively more complex <i>abX</i> grammar with a nonadjacent relationship between <i>a</i> and <i>X</i>. Participants were tested on their generalization of the grammatical pattern to new sequences with novel <i>X</i> elements that conformed to (<i>aX, abX</i>) or violated (<i>Xa, baX</i>) the grammars.<b>Results: </b>Results revealed an interaction between age and language group. Four-year-olds with and without DLD performed equivalently on the <i>aX</i> and <i>abX</i> 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 <i>aX</i> tests compared to participants with DLD, but the groups’ <i>abX</i> 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 <i>aX</i> performance positively predicted learning outcomes on the subsequent <i>abX</i> grammar for TD participants.<b>Conclusion: </b>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.<b>Supplemental Material S1.</b> Pearson correlations between executive function scores and artificial grammar learning.Kapa, L. L., &amp; Mettler, H. M. (2024). Statistical learning among preschoolers with and without developmental language disorder: Examining effects of language status, age, and prior learning. <i>Journal of Speech, Language, and Hearing Research</i>, <i>67</i>(9), 3081–3093. https://doi.org/10.1044/2024_JSLHR-23-00602