Frota, S. , Butler, J. , Severino, C. & Vigario, M.
Lisbon Baby Lab, Centro de Linguistica, Universidade de Lisboa; Portugal
The validity of the European Portuguese CDI Short Forms (EP-CDI SF) in identifying language-impaired children (LI) and children at-risk for language impairment (AR) in comparison to typical development (TD), referring to the EP norms, was investigated. Language deficits are pervasive in Down Syndrome, and younger siblings of children with ASD or SLI, as well as low birth-weight/premature children are known to be at risk for language impairment. In prospective studies, samples of LI (Down Syndrome), AR and TD children were followed between 8 and 30 months, with language abilities measured at 12, 18 24 and 30 months (EP-CDI SF). Significant differences emerged as early as 12 between LI and TD (receptive and expressive lexicon); for comprehension, twice as many AR than TD scored below the 5th percentile at 12; for production, 80-90% of AR scored below the 5th and 10th percentiles at 12 and 30, close to scores for LI. AR had smaller lexicons than TD (but larger than LI) at 12, and reduced lexicon growth at 24 and 30 compared to TD. Two critical age points are suggested to signal AR children early in development: 12 months, recommending monitoring/early intervention, and 30 months confirming continued intervention and developmental evaluation.