ERIC Number: EJ1034639
Record Type: Journal
Publication Date: 2014-Apr
Abstractor: As Provided
Reference Count: N/A
Modeling Mechanisms of Persisting and Resolving Delay in Language Development
Thomas, Michael S. C.; Knowland, V. C. P.
Journal of Speech, Language, and Hearing Research, v57 n2 p467-483 Apr 2014
Purpose: In this study, the authors used neural network modeling to investigate the possible mechanistic basis of developmental language delay and to test the viability of the hypothesis that persisting delay and resolving delay lie on a mechanistic continuum with normal development. Method: The authors used a population modeling approach to study individual rates of development in 1,000 simulated individuals acquiring a notional language domain (in this study, represented by English past tense). Variation was caused by differences in internal neurocomputational learning parameters as well as the richness of the language environment. An early language delay group was diagnosed, and individual trajectories were then traced. Results: Quantitative variations in learning mechanisms were sufficient to produce persisting delay and resolving delay subgroups in similar proportions to empirical observations. In the model, persisting language delay was caused by limitations in processing capacity, whereas resolving delay was caused by low plasticity. Richness of the language environment did not predict the emergence of persisting delay but did predict the final ability levels of individuals with resolving delay. Conclusion: Mechanistically, it is viable that persisting delay and resolving delay are only quantitatively different. There may be an interaction between environmental factors and outcome groups, with individuals who have resolving delay being influenced more by the richness of the language environment.
Descriptors: Language Impairments, Delayed Speech, Hypothesis Testing, Neurological Organization, Neurological Impairments, Language Acquisition, Simulation, English, Language Processing, Environmental Influences, Interaction
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A