The purpose of the present study was to examine working memory (WM) capacity, lexical access and phonological skills in 19 children with cochlear implants (CI) (5;7-13;4 years of age) attending grades 0-2, 4, 5 and 6 and to compare their performance with 56 children with normal hearing. Their performance was also studied in relation to demographic factors. The findings indicate that children with CI had visuospatial WM capacities equivalent to the comparison group. They had lower performance levels on most of the other cognitive tests. Significant differences between the groups were not found in all grades and a number of children with CI performed within 1 SD of the mean of their respective grade-matched comparison group on most of the cognitive measures. The differences between the groups were particularly prominent in tasks of phonological WM. The results are discussed with respect to the effects of cochlear implants on cognitive development

The purpose of the present article is to present an overview of a set of studies conducted in our own laboratory on cognitive and communicative development in children with cochlear implants (CI). The results demonstrate that children with CIs perform at significantly lower levels on the majority of the cognitive tasks. The exceptions to this trend are tasks with relatively lower demands on phonological processing. A fairly high proportion of the children can reach a level of reading comprehension that matches hearing children, despite the fact that they have relatively poor phonological skills. General working memory capacity is further correlated with the type of questions asked in a referential communication task. The results are discussed with respect to issues related to education and rehabilitation.

The deaf teenagers with CI in the study seem to be equally collaborative and responsible conversational partners as the hearing teenagers. The interpretation is that certain conditions in this study facilitate their participation in conversation. Such conditions might be a calm environment, a task that is structured and without time limits and that the partner is well known to the teenager with CI.

In this study, we explored the influence of time factors (age at implant, time with cochlear implant and age), complex working memory and phonological short-term memory on lexical and grammatical development in congenitally deaf children with cochlear implants. Fifteen children (aged 5 years 4 months to 11 years 5 months) were examined with the use of several linguistic and cognitive measures after a minimum of 18 months of implant use. Phonological short-term memory was assessed with non-word repetition, where the percentage of correctly repeated consonants and vowels was counted. For the assessment of lexical acquisition. a novel word learning task was administered. Receptive and expressive grammar was tested. Our results corroborate earlier findings on the influence of phonological short-term memory on novel word learning. The percentage of vowels correctly produced in non-word repetition was more important in this group than age at implant, not only for novel word learning. but also for receptive and expressive grammar.

Complex working memory seems to play a significant role in vocabulary acquisition in primary school age children. The interpretation is that the results support theories suggesting a weakened influence of phonological short-term memory on novel word learning in school age children.