Enhancing Working Memory Capacity in Persian Cochlear Implanted Children: A Clinical Trial Study

Document Type : Original


1 Department of Audiology, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran and Rehabilitation Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.

2 Department of Speech Therapy, School of Rehabilitation Sciences, Shiraz University of Medical Sciences, Shiraz, Iran and Rehabilitation Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.

3 Department of Audiology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.

4 Department of Otolaryngology, Shiraz University of Medical Sciences, Shiraz, Iran.

5 Fars Cochlear Implant Center, Shiraz University of Medical Sciences, Shiraz, Iran.

6 Department of Biostatistics, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.


Sensory deprivations such as hearing impairment that affect sensory input have a secondary impact on cognitive functions such as working memory (WM). WM capacity is an important cognitive component that processes language-related activities. Moreover, several studies have shown a deficit in WM in children with a cochlear implant (CI). We aimed to assess the performance of children with CIs in pre- and post-training sessions and compare their scores on a battery of WM tests to investigate the efficacy of a WM training program.
 Materials and Methods:
Twenty-five children aged 7–10 years with a CI participated in this study. To train their WM, a computer game was used. In order to examine auditory WM, a test battery including standardized digit span (forward and backward variations), non-word and sentence repetition (subtest of the Test of Language Development–Primary) were assessed in pre- and post-training test sessions at Shiraz Implant Center.
There were statistically significant differences between pre- and post-training test scores on all subtests. Test score differences were statistically significant for forward digit span (P=0.003), backward digit span (P=0.001), non-word repetition (P=0.001), and sentence repetition tasks (P=0.003) before and after training sessions.
Training may enhance WM capacity. With regards to the importance of WM in literacy and learning, it seems applying such intervention programs may be helpful in the rehabilitation of implanted children.


Main Subjects

1. Harden AL. A review of research on working memory and its importance in education of the deaf [thesis], Program in audiology and communication sciences, Washington University School of medicine 2011.
2. Baddeley. Working memory and language: an overview. J Commun Disorder. 2003;36:189–208.
3. Klingberg T. Training and plasticity of working memory. Trends Cogn Sci. 2010;14:317–24.
4. Kronenberger WG, Pisoni DB, Henning SC, Colson BG, Hazzard LM. Working memory training for children with cochlear implants: a pilot study. J Speech Lang Hear Res. 2011;54:1182–96.
5. Bharadwaj SVG, L. Allman, T. Working memory, short term memory and reading proficiency in school-age children with cochlear implants. Int J Pediatr Otorhinolaryngol. 2015; 79: 1647–53.
6. Nittrouer S, Caldwell-Tarr A, Lowenstein JH. Working memory in children with cochlear implants: problems are in storage, not processing. Int J Pediatr Otorhinolaryngol. 2013;77(11):1886–98.
7. Pisoni DB, Cleary M. Measures of working memory span and verbal rehearsal speed in deaf children after cochlear implantation. Ear Hear. 2003; 24(1 Suppl):106S–20S.
8. Soleymani Z, Amidfar M, Dadgar H, Jalaie S. Working memory in Farsi-speaking children with normal development and cochlear implant. Int J Pediatr Otorhinolaryngol. 2014;78:674–8.
9. Rosenthal EN, Riccio CA, Gsanger KM, Jarratt KP. Digit span components as predictors of attention problems and executive functioning in children. Arch Clin Neuropsychol. 2006;21 131–9.
10. Dillon CM, Pisoni DB. Non word Repetition and Reading Skills in Children Who Are Deaf and Have Cochlear Implants. Volta Rev. 2006; 106: 121–45.
11. Moossavi A, Khavarghazalani B, Lotfi Y, Mehrkian S, Bakhshi E, Bakhtiari BM. Validity and reliability of a non-sense syllable test for evaluating phonological working memory in Persian speaking children (In Persian). Audiol. 2014; 23:31–9.
12. Gathercole SE, Willis CS, Baddeley AD, Emslie H. The children’s test of nonword repetition: a test of phonological working memory. Memory. 1994; 2:103–27.
13. Gray S. Diagnostic accuracy and test-retest reliability of nonword repetition and digit span tasks administered to preschool children with specific language impairment. J Commun Disord. 2003; 36: 129–51.
14. Nittrouer S, Caldwell-Tarr A, Sansom E, Twersky J, Lowenstein JH. Nonword repetition in children with cochlear implants: a potential clinical marker of poor language acquisition. Am J Speech Lang Pathol. 2014;23:679–95.
15. Dillon CM, Burkholder RA, Cleary M, Pisoni DB. Nonword repetition by children with cochlear implants: accuracy ratings from normal-hearing listeners. J Speech Lang Hear Res. 2004;47:     1103–16.
16. Hasanzadeh SM, Adaptation and Normalization of test of language development primary (TOLD-P3) in Persian language children in Tehran. [In Persian]. Research on Exceptional children. 2001; 1: 35–51.
17. Klem M, Melby Lervåg M, Hagtvet B, Lyster SAH, Gustafsson JE, Hulme C. Sentence repetition is a measure of children's language skills rather than working memory limitations. Developmental Science. 2015;18:146–54.
18. Rahimi M, Sadighi F, Razeghi S. A comparison of Linguistic Skills between Persian Cochlear Implant and Normal Hearing Children. Iranian Rehabilitation Journal. 2013;11:11–9.
19. Seeff‐Gabriel B, Chiat S, Dodd B. Sentence imitation as a tool in identifying expressive morphosyntactic difficulties in children with severe speech difficulties. Int J Lang Commun Disord. 2010;45:691–702.
20. Poll GH, Miller CA, Mainela‐Arnold E, Adams KD, Misra M, Park JS. Effects of children's working memory capacity and processing speed on their sentence imitation performance. Int J Lang Commun Disord. 2013;48:329–42.
21. Archibald LM, Joanisse MF. On the sensitivity and specificity of nonword repetition and sentence recall to language and memory impairments in children. J Speech Lang Hear Res. 2009;52: 899–914.
22. Beer J, Pisoni DB, Kronenberger W. Executive function in children with cochlear implants: The role of organizational-integrative processes. Volta Voices. 2009;16:18–21.
23. Figueras B, Edwards L, Langdon D. Executive function and language in deaf children. J Deaf Stud Deaf Educ. 2008;13:362–77.
24. Pisoni D, Kronenberger W, Roman A, Geers A. Article 7: Measures of digit span and verbal
rehearsal speed in deaf children following more than 10 years of cochlear implantation. Ear Hearing. 2011; 32:60s.
25. Briner TL, Buchanan JB, Chavis SE, Chen S-y, Iannuzzi GL, Kashtelyan V. Cognitive training: the effects of working memory training [disserta­tion]. Maryland Univ.; 2011.
26. Ingvalson EM, Wong PC. Training to improve language outcomes in cochlear implant recipients. Front Psychol. 2013;4:263.
27. Casserly ED, Pisoni DB. Nonword repetition as a predictor of long-term speech and language skills in children with cochlear implants. Otol Neurotol. 2013;34:460–70.
28. Beer J, Kronenberger WG, Pisoni DB. Executive function in everyday life: Implications for young cochlear implant users. Cochlear Implants Int. 2011;12(Suppl 1):S89–S91.
29. Conway CM, Pisoni DB, Kronenberger WG. The importance of sound for cognitive sequencing abilities: The auditory scaffolding hypothesis. Curr Dir Psychol Sci. 2009;18:275–9.
30. Buschkuehl M, Jaeggi SM, Jonides J. Neuronal effects following working memory training. Dev Cogn Neurosci. 2012;2:S167–S79.
31. Geers AE. Predictors of reading skill development in children with early cochlear implantation. Ear Hearing. 2003;24:59S–68S.
32. Pisoni DD, Geers AE. Working memory in deaf children with cochlear implants: Correlations between digit span and measures of spoken language processing. Ann Otol Rhinol Laryngol Suppl. 2000;185:92–3.
33. Garrison W, Long G, Dowaliby F. Working memory capacity and comprehension processes in deaf readers. J Deaf Stud Deaf Educ. 1997;2:78–94.
34. Gathercole SE. Nonword repetition and word learning: The nature of the relationship. Appl Psycholinguist. 2006;27:513–43.
35. Cain K, Oakhill JV, Barnes MA, Bryant PE. Comprehension skill, inference-making ability, and their relation to knowledge. Mem Cognit. 2001; 29: 850–9.