Eye-tracking studies on developmental language disorder: a systematic review

Developmental language disorder (DLD) is a neurodevelopmental condition characterized by persistent difficulties in language acquisition and processing. While traditional behavioral and neurophysiological methods have provided valuable insights, eye-tracking has emerged as a powerful tool for capturing real-time cognitive processing during language comprehension. However, evidence from eye-tracking studies in DLD remains underrepresented and fragmented across linguistic domains and experimental paradigms. This systematic review synthesizes 33 empirical studies and examines how eye-tracking has been used to investigate real-time language processing in children with DLD. The review focuses on three key dimensions: (a) cognitive-linguistic domains addressed, (b) paradigms and eye-movement metrics employed, and (c) recurring processing differences between children with DLD and typically developing (TD) counterparts. The synthesis reveals three broadly consistent processing patterns in DLD: slower processing efficiency, reduced predictive processing, and increased reliance on semantic cues over morphosyntactic information. These patterns suggest that language difficulties in DLD are not solely attributable to representational deficits but are closely linked to inefficiencies in real-time integration and competition resolution during language processing. By consolidating findings across paradigms, this review provides a cognitively grounded account of DLD and highlights the role of eye-tracking in uncovering underlying processing mechanisms. Implications for theoretical models of language processing and future methodological directions are discussed.