Assessment of working memory components in children with cochlear implants: evidence for modality-specific deficits

Abstract Background Cochlear implants (CIs) restore auditory sensation, yet pediatric users frequently exhibit persistent deficits in higher-order language and cognitive skills. Working memory (WM) is a critical predictor of language acquisition and academic achievement. This study aimed to characterize the WM profile of school-aged children with unilateral CIs within Baddeley’s multicomponent framework. Methods This case-control study included 25 children with prelingual bilateral severe-to-profound sensorineural hearing loss and unilateral CI, and 25 age-matched normal-hearing (NH) controls (6–13 years). All participants completed an Arabic WM test battery evaluating the central executive, phonological loop, episodic buffer, and visuospatial sketchpad. Intelligence quotient (IQ) and language age were also assessed. Results The CI group performed significantly worse than NH peers on all verbal WM tasks: central executive (listening span, sentence completion and recall, number-letter sequence recall, verbal span; all p < 0.001), phonological loop (digit span, non-word repetition; p < 0.001), and episodic buffer (sentence repetition; p < 0.001). In contrast, visuospatial sketchpad performance on the maze test did not differ significantly ( p = 0.935), although block recall showed a modest group difference ( p = 0.013). IQ was significantly lower in the CI group (88.8 ± 5.8 vs. 97.5 ± 9.6; p < 0.001). Duration of implantation and language age correlated positively with specific WM components, whereas chronological age did not correlate with WM performance in the CI group. Conclusion Children with CIs demonstrated greater difficulties in aspects of verbal WM that persists despite long-term implant use. The dissociation between impaired verbal and preserved visuospatial WM supports the effortful listening hypothesis and highlights the need for visually supported educational interventions and early implantation.