|General programme, activity sheet|
||Friday 19 September, 2014
Language development in cochlear implant users: A dual-stream neurolinguistic analysis
Authors: Moreno-Torres, Ignacio, Madrid-Cánovas, Sonia, Moruno-López, Esther, Blanco, Gema
This study adopts a dual-stream neurolinguistic model to explore the long term outcomes of a group of Spanish learning pediatric cochlear implant (CI) users. According to this model, the brain has at least two parallel and functinoally segregated linguistic processing streams (Hickok, 2012), one involved in auditory-motor segmental level associations (ie. the dorsal stream) and another requiring less acoustic details and providing access to conceptual representations (i.e. the ventral stream). We advance the hypothesis that, due to the limited information provided by their devices, CI users show selective deficits in the dorsal stream. Three predictions of this hypothesis are presented and evaluated: 1) CI users struggle to develop those tasks which are supported by the dorsal strem (articulation and phonological working memory). 2) Early in development CI users do not show poor receptive language; however, due to the role of WM for lexical development, their receptive language will develop slowly; 3) Their long-term outcomes will be very much determined by the environmental conditions.
The data was obtained from a a group of 10 CI users who participated in a longitudinal study. All the children lived in monolingual Spanish families. The mean age at CI activation was 18 months. The children were followed for four years. Early receptive language data was obtained from the receptive lexicon subtest of the MacArthur inventory. A measure of receptive language was obtained after 3 and 4 years of implant use. Measures of articulation and phonological WM were obtained by means of repetition tasks. The children’s families were rated according to a scale measuring the degree of implication in rehabilitation.
The results confirmed the main predictions.1) CI children show important articulation and WM deficits; 2) after 12 months of CI use their receptive language was significantly higher than that of typical 12 month olds, but three years later the advantage had disappeared; 3) Familiy implication was correlated with the scores in in receptive language. We conclude that the dual stream models offers a plausible framework to explain the outcomes of CI users.
Place: Main Room