Executive functions in preschool and school-age cochlear implant users. Do they differ from their hearing peers? A systematic review and meta-analysis

Purpose: Executive functions (EF) play a fundamental role in planning and executing goal-driven behaviours. The purpose of this systematic review and meta-analysis was to investigate EF skills mastered by preschool/school-age cochlear implanted children (CIC) without morpho-functional abnormalities and to compare their outcomes with typically hearing children (THC). Methods: Bibliographic search for observational studies of any language/date up to 16 December 2022 was performed with the following electronic databases: PubMed, Scopus, and Web of Science. After removal of duplicates, 2442 records were subjected to a three-stage screening process and 83 potentially eligible articles were identified. A total of 15 studies was included in the final analysis: 9 articles directly meeting the eligibility criteria plus 6 more studies thanks to the Authors sharing their dataset, specifically for participants who met present inclusion criteria. Results: Meta-analysis showed a statistically significant difference only for verbal short-term memory whereas group differences for visuospatial short-term memory and verbal/visuospatial working memory were not significant. For fluency skills, meta-analysis revealed statistical significance for the semantic fluency task but not for the rapid naming test. Qualitative analysis reflected group similarities in flexibility but CIC’s difficulties in auditory attention/planning skills. Controversial findings for inhibitory control skills were observed. Conclusion: EF performance comparisons between CIC and THC show inter-skill and inter-test variances. Due to the paucity of existing studies, present findings should be interpreted with caution. Future research in this domain is strongly recommended.