Language Learning Impairments in Children

Abstract

This article summarizes the deficit profile for those children who are unable to master spoken and written language comprehension and production despite having normal nonverbal intelligence, hearing acuity, and speech motor skills, and no overt physical disability, recognized syndrome, or other mitigating medical factors known to cause language disorders in children. Approximately 7% of school-aged children have primary language impairment (PLI). The ratio of males to females with PLI is 1.1:1. Both genetic and environmental factors are important etiological factors. Nonlinguistic factors such as implicit learning, memory, attention, and fluid intelligence play a key role in both the acquisition and use of phonological, lexical, morphological, and syntactic aspects of language for these children. Widely varying brain structures and functions, as measured by MRI, fMRI, fNIRS, SPECT, event-related potential (ERP), and MEG, suggest atypical brain anatomy and patterns of functional asymmetry of language cortex and cortical dysplasia in these children and their family members. Auditory ERPs also indicate slower processing at higher cognitive levels and abnormalities in later stages of auditory processing in PLI. Research to date has focused on determining whether PLI is a primary deficit in an independent grammar module, or secondary to impairments in general-purpose cognitive mechanisms. New evidence suggests that general learning mechanisms involved in implicit learning are impaired in children with PLI.