Tina Ibertsson

Cognitive and linguistic skills in Swedish children with cochlear implants – measures of accuracy and latency as indicators of development

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.

Cognitive development in children with cochlear implants: Relations to reading and communication

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.

Cognitive development, reading and prosodic skills in children with cochlear implants

This report summarizes some of the results of studies in our laboratory exploring the development of cognitive, reading and prosodic skills in children with cochlear implantation (CI). The children with CI performed at significantly lower levels than the hearing comparison group on the majority of cognitive tests, despite showing levels of nonverbal ability. The differences between children with CI and hearing children were most pronounced on tasks with relatively high phonological processing demands, but they were not limited to phonological processing. Impairment of receptive and productive prosody was also evident in children with CI. Despite these difficulties, 75% of the children with CI reached a level of reading skill comparable to that of hearing children. The results are discussed with respect to compensation strategies in reading.

A methodological contribution to the assessment of nonword repetition-a comparison between children with specific language impairment and hearing-impaired children with hearing aids or cochlear implants.

Poor nonword repetition is considered as a clinical marker of specific language impairment (SLI). In children with expressive language problems, the analysis and scoring procedures are often insufficiently described. We argue for a combined analysis of segmental and suprasegmental accuracy in nonword repetition tasks as well as an appreciation of gender differences. The view is taken based on empirical findings in a comparison between children with specific language impairment, children with mild/moderate hearing impairment and hearing aids (HI), and children with severe to profound hearing impairment with cochlear implants (CI). With age and gender taken into consideration, the main effects of both group and syllable level on a combined measure of segmental and suprasegmental accuracy remained. Although not necessarily an index of limited working memory capacity, persistently poor imitation of nonwords might be an indication of language impairment in children with mild/moderate HI and in children with CI.

Deaf teenagers with cochlear implants in conversation with hearing peers

BACKGROUNDnThis study investigates the use of requests for clarification in conversations between teenagers with a cochlear implant (CI) and hearing peers. So far very few studies have focused on conversational abilities in children with CI.nnnAIMSnThe aim was to explore co-construction of dialogue in a referential communication task and the participation of the teenagers with CI in comparison with individually matched hearing children and teenagers (HC) by studying the use of requests for clarification.nnnMETHODS & PROCEDURESnSixteen conversational pairs participated: eight pairs consisting of a child with CI and his/her hearing conversational partner (CIP); and eight pairs consisting of an HC and a conversational partner (HCP). The conversational pairs were videotaped while carrying out a referential communication task requiring the description of two sets of pictures depicting faces. The dialogues were transcribed and analysed with respect to the number of words and turns, the time it took for each pair to complete the tasks, and the occurrence and different types of requests for clarification that were used in each type of conversational pair and in each type of dialogue.nnnOUTCOMES & RESULTSnThe main finding was that the teenagers with CI produced significantly more requests for clarification than the HCs. The most frequently used type of request for clarification in all dialogues was request for confirmation of new information. Furthermore, there was a trend for the teenagers with CI to use this type of request more often than the HC. In contrast, the teenagers with CI used significantly fewer requests for confirmation of already given information and fewer requests for elaboration than the HC.nnnCONCLUSIONS & IMPLICATIONSnThe 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.

Picture-elicited written narratives, process and product, in 18 children with cochlear implants

The purpose of the study was to explore the narrative writing of 18 children, ages 11 to 19, with severe and profound hearing impairment who had cochlear implants (CI), compared with the performance of hearing children. Nine of the 18 children had prelingual deafness and 9 children had postlingual deafness. The hearing impairment was progressive in 11 children. The participants thus formed a heterogeneous group, which was split in two ways: according to age at testing and age at implantation. The narratives were collected by means of keystroke logging. The difference between the children with CI and the hearing children was most prominent for two measures: the percentage of pause time (in the group of children older than 13 years) and lexical density. Furthermore, the children implanted after 5 years of age performed more like the hearing children. This group consisted of children with postlingual deafness and also of children who were deafened progressively. Our interpretation is that these children benefited from the early linguistic input. Taking the whole group of participants into consideration, the results reflect linguistic and cognitive processing limitations in complex linguistic tasks like narration for the children with CI in comparison with their hearing peers.

Vowel spaces in Swedish adolescents with cochlear implants

This paper examines vowel production in Swedish adolescents with cochlear implants. Twelve adolescents with cochlear implants and 11 adolescents with normal hearing participated. Measurements were made of the first and second formants in all the nine long Swedish vowels. The values in hertz were bark-transformed, and two measures of the size of the vowel space were obtained. The first of them was the average Euclidean distance in the F1-F2 plane between the nine vowels and the mean F1 and F2 values of all the vowels. The second was the mean Euclidean distance in the F1-F2 plane between all the vowels. The results showed a significant difference for both vowel space measures between the two groups of adolescents. The cochlear implant users had a smaller space than the adolescents with normal hearing. In general, the size of the vowel space showed no correlations with measures of receptive and productive linguistic abilities. However, the results of an identification test showed that the listeners made more confusions of the vowels produced by speakers who had a small mean distance in the F1-F2 plane between all the vowels.

‘You sometimes get more than you ask for’: responses in referential communication between children and adolescents with cochlear implant and hearing peers

BACKGROUNDnThis study investigates responses to requests for clarification in conversations between children/adolescents with cochlear implant (CI) and normally hearing peers. Earlier studies have interpreted a more frequent use of requests of confirmation (yes/no interrogatives) in the CI group as a conversational strategy used to prevent communication breakdowns and control the development of the conversation. This study provides a continuation of this line of research, now focusing on responses to requests for clarification.nnnAIMSnThe aim was to examine the type and distribution of responses to requests for clarification in a referential communication task. In addition, we analysed the compliance between the type of response and the type of request as a measure of mutual adaptation.nnnMETHODS & PROCEDURESnTwenty-six conversational pairs aged 10-19 years participated: 13 pairs consisting of a child/adolescent with CI (CI) and a conversational partner (CIP); and 13 pairs consisting of a normally hearing control (NH) and a conversational partner (NHP). The pairs performed a referential communication task requiring the description of faces. All occurrences of requests for clarification and their responses in the dialogues were identified and categorized. We also analysed how the different types of requests and responses were combined and the type-conformity of the responses to requests for confirmation.nnnOUTCOMES & RESULTSnThe results showed no significant group differences regarding type, distribution or type-conformity of responses. In all four groups (CI, CIP, NH and NHP), a discrepancy between the request and the response was found, indicating that the response provided information that was not explicitly requested. Requests for confirmation constituted 78-90% of the requests, whereas only 54-61% of responses were confirmations. Conversely, the proportion of requests for elaboration was 6-15%, whereas the proportion of elaborated responses was 34-40%.nnnCONCLUSIONS & IMPLICATIONSnThe children/adolescents with CI contribute equally to the conversation regarding type and distribution of responses to requests for clarification. The frequent use of elaborated responses indicates common ground for the conversational partners and a shared understanding of the objective of the task. The context creates facilitative conditions, with positive interactional consequences. The results have implications for the design of intervention, where tasks such as this can be used to make children with CI more aware of the role of questioning strategies in interaction.

Cognitive Skills and Reading Ability in Children with Cochlear Implants

(2010). Cognitive Skills and Reading Ability in Children with Cochlear Implants. Cochlear Implants International: Vol. 11, Proceedings of the 9th European Symposium on Paediatric Cochlear Implantation, Warsaw, 2009, pp. 395-398.

Development of cognitive and reading skills in deaf children with CIs

Auditory stimulation provided by a cochlear implant (CI) to deaf or severely hearing-impaired children has an impact on their development in most areas (Geers et al., 2008; Lyxell et al., 2008, 2009; Pisoni et al., 2008; Wass, 2009; Wass et al., 2008). This is especially obvious in the cognitive and communicative domains (Pisoni et al., 2008; Wass, 2009). Previous research indicates that deaf children with CIs generally outperform deaf children without CI implants in most cognitive and communicative tasks. Early implantation is also more beneficial for cognitve development than later implantation (Pisoni et al., 2008; Sharma et al., 2005; Tait et al., 2007; Wass, 2009). The purpose of the present article is to present an overview and summary of results from some recent studies carried out in our own laboratory. Focus is on the development of working memory (WM) capacity, phonological, and lexical skills (AskerArnason et al., 2007; Lyxell et al., 2008; Wass, 2009; Wass et al., 2008). These three basic cognitive components were chosen because they are central to development of a number of other fundamental cognitive activities including reading, mental arithmetic, and verbal communication. WM refers to the ability to simultaneously store and process information over a short period of time (12–15 seconds). Previous research has demonstrated that children with CI have shorter verbal memory spans compared to age-matched hearing children (Pisoni, 2008). In our own studies we have attempted to further examine WM by examining different components of the WM system (i.e. the central executive, the visual, and phonological part, cf., Repovs and Baddeley, 2006). Phonological processing skill refers to the ability to identify and manipulate phonological-related material. Phonological skills are highly correlated in hearing children with literacy skills, such as reading and writing. Atypical development is often associated with reading problems. The empirical picture from previous research is very clear. Children with CI perform at a substantially lower level than agematched hearing children. Lexical access refers to speed and accuracy in finding and retrieving verbal labels from long-term memory. Lexical access is a strong predictor of reading and spelling performance in hearing children. Previous research has revealed that deaf children with CI can reach levels of reading comprehension comparable to those of normal hearing children, although not all of them do so (c.f., Geers et al., 2008). Focus in our studies has been on two aspects of reading, comprehension, and decoding of words and non-words.