Paper Critique (click the link to view the paper)
Narrative spoken language skills in severely hearing impaired school-aged children with cochlear implants.
Tinne Boons, Leo De Raeve, Margreet Langereis, Louis Peeraer, Jan Wouters, Astrid van Wieringen.
My last blog post was about my favourite tissue (the human ear)! Cochlear implants are one of the treatments that are used to treat patients that are deaf due to hair cell damage. It is a very common treatment in children with sensorineural hearing loss. This blog includes a critique on a paper about narrative skills in children with cochlear implants.
Figure 1: Cochlear Implant
Background: Many newborns are affected by congenital hearing loss and cochlear implants (which are a surgically placed electronic device) are often used as a treatment. An external microphone and sound processor are worn to pick up sounds. These signals become an electric code which are transmitted to an implanted electrode that will stimulate the auditory nerve and allow for neuron growth. This study looks at narratives (a spoken account of a story) of deaf children with cochlear implants with matched normal hearing peers to see how the cochlear implant affects the child's narrative abilities (first goal of the study). Narrative skills are a complex form of language that begin in the child's preschool years and develops throughout the school years. These skills are a good predictor of reading comprehension and writing skills. Another goal of this study was to look at a high potential subgroup to see how this group compared to the normal hearing children (see methods for criteria of this high potential subgroup).
Methods: This study is a cross-sectional, prospective multi-centre study. Participants were chosen from two cochlear implant centers and one school for the deaf (consent was given by parents). The participants needed to have congenital deafness or deafness occuring before the age of one, have cochlear implants placed before the age of 5, be of school-age and have a normal intellectual ability. There were 66 children selected and each hearing impaired child was matched with a normal hearing child of the same age (maximum of 3 months difference in age), same sex, and living in the same area. The goal of this part of the study was to see how hearing impaired children with cochlear implants differ from normal hearing children. A high potential subgroup was chosen as well who had cochlear implants before the age of 2, bilateral implants, no other disabilities and only one spoken language in the home. This subgroup was compared to a control group (normal hearing children).
The test was conducted by using the Bus Story subtest of the Renfrew language scale to measure the spoken narrative ability of the children. The bus story was spoken by a speech pathologist and the children had to retell the story with picture support. The retelling of the story was videotaped and the narrative abilities were rated on a micro and macro level. Five trained raters scored the children. At the macro level they looked at the global organization (child's ability to tell a hierarchal representation of the main parts of the story). At the micro level they were scored on narrative productivity (length of utterances, incorrect utterances), coherence, and errors in morphology, semantics, etc. The parents involvement in the child's rehabilitation was also rated by getting the parents to complete a questionnaire.
Results: For the group of matched normal hearing children and children with
cochlear implants(CI's) (referred to as total group in the paper) it was found that children with CI's had problems in reproducing the theme of the story. In comparison to the normal hearing children they gave less complete setting, initiating, episodic and solution elements. At the micro level both groups of children had similar numbers of utterances but the length and complexity of utterances was lower for children with cochlear implants and they also had more incorrect utterances. There was no difference in the coherence between the two groups and the distribution of error types was similar for both groups. These results show that cochlear implants do have a positive effect on narrative development but the children with the implants did show a delay compared to the normal hearing group.
The high potential subgroup was compared to a control group (normal hearing children). The plot structure and efficiency of retelling the bus story was similar for both groups. At the micro level there was very little difference in narrative productivity except children with CIs had more incorrect utterances. Both had similar coherence and there was no significant difference in semantic, morphological, or syntax errors. The high potential CI group had more incorrect utterances but their retold bus story did not differ from the normal hearing children in any other way. This group shows high prospects for children who have bilateral CI's placed before age two and have no other disabilities and only one spoken language at home. These children can achieve results very similar to normal hearing children (however this can differ on an individual basis). The high potential subgroup also had educated parents who were highly involved in the rehabilitation which could have made a difference as well.
Personal Critique: I enjoyed the paper and found the topic was quite interesting. The authors gave a good background on narratives and cochlear implants which helped me understand the concepts. They also gave clear statements on the goals of the study. I think that the terminology could have been explained better to make the results easier to understand (for example explaining terms such as subordinate clauses, and subsidiary story elements). The methods of the study were appropriate, and enabled the narrative skills of the cochlear implant children to be compared to the normal hearing group and the high potential subgroup to be compared to the control group.Cochlear implants were found to have a positive effect but these children lack the narrative skills of their hearing peers.They also found high prospects for the high potential subgroup. Therefore, the authors met the goals of their study(goals are listed in the background section). The results were explained well and in an organized manner (headings for total group and subgroup, micro and macro levels). However, I think the figures in the results section could be improved. They used a lot of tables which contained too much information and were very hard to follow. Figures showing general trends would be helpful. The results of the high potential subgroup show high prospects for the future. If children get bilateral cochlear implants early and have high parent involvement they can reach narrative goals of their normal hearing peers. This information is very helpful and hopefully can improve the lives of hearing impaired children and their parents. (It is suggested that a further study on parent involvement in rehabilitation should be conducted).
Paper Reference: Boons, T., De Raeve, L., Langereis, M., Peeraer, L., Wouters, J., & Van Wieringen, A. 2013. Narrative spoken language skills in severely hearing impaired school-aged children with cochlear implants. Research in Developmental Disabilities 34: 3833-3846.
I'll conclude my blog with this very cute picture:)
