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

Summary

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.

Conditions

• Developmental Language Disorder

Interventions

BEHAVIORAL

Eye-Tracking in Visual World Paradigm

Participants complete six eye tracking tasks. They see images on a computer screen are tasked with finding a specific picture or saying a specific word (target). We track their eye movements to the visual representations of the target compared with their eye movements to visual representations of items that are similar to the target.

Sponsors & Collaborators

• National Institutes of Health (NIH)

  collaborator NIH

• National Institute on Deafness and Other Communication Disorders (NIDCD)

  collaborator NIH

• University of Iowa

  lead OTHER

Principal Investigators

• Stewart McCauley, PhD · University of Iowa

• Si On Yoon, PhD · University of Iowa

• Philip Combiths, PhD · University of Iowa

• J. Bruce Tomblin, PhD · University of Iowa

• Jacob Oleson, PhD · University of Iowa

Eligibility

Min Age

30 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-04-17

Primary Completion

2026-07-31

Completion

2027-07-31

Countries

• United States

Study Locations