Language Outcomes, Mechanisms, and Trajectories in Adults With and Without Developmental Language Disorder

The investigators' overall objective is to characterize the long-term outcomes of Developmental Language Disorder (DLD) in adulthood and to identify specific cognitive mechanisms mediating these outcomes. To address their objectives, the investigators utilize a large, pre-existing dataset and participant pool from one of the most comprehensive examinations of DLD to date: the Iowa Longitudinal Study. The investigators will re-recruit subjects with DLD and with typical language from this historic cohort, who are now adults (30-35 years old). In Aim 1, the investigators will use measures from kindergarten through 10th grade and collect new outcome measures in adulthood to characterize the long-term outcomes of DLD. The investigators predict that adults with DLD will diverge from adults with TL in language skills that are more complex and higher-level language skills that are important for communication in the workplace. Further, the investigators predict a fanning effect: some children with DLD will "catch up" to their TL peers in adulthood, some will show evidence of a decline, and others will show stable trajectories. In Aim 2, the investigators measure real-time competition across written and spoken language using eye-tracking. According to speed of processing accounts adults with DLD may be slower than their TL peers to activate competitors and targets. According to working memory accounts adults with DLD will show sustained competitor activation. Further, the investigators predict that measures related to the dynamics of competition (speed of activation and timing of competitor suppression) will account for variation in language outcomes in adults.

NCT Number	NCT06898671
Lead Sponsor	University of Iowa Collaborators: National Institutes of Health (NIH), National Institute on Deafness and Other Communication Disorders (NIDCD)
Conditions	Developmental Language Disorder
Enrollment	400 participants
Start Date	2023-04-17
Primary Completion	2026-07 (estimated)
Study Completion	2027-07 (estimated)
Updated on ClinicalTrials.gov	2025-03-27