Verbal Working Memory in Children With Cochlear Implants

Abstract

Purpose Verbal working memory in children with cochlear implants and children with normal hearing was examined. Participants Ninety-three fourth graders (47 with normal hearing, 46 with cochlear implants) participated, all of whom were in a longitudinal study and had working memory assessed 2 years earlier. Method A dual-component model of working memory was adopted, and a serial recall task measured storage and processing. Potential predictor variables were phonological awareness, vocabulary knowledge, nonverbal IQ, and several treatment variables. Potential dependent functions were literacy, expressive language, and speech-in-noise recognition. Results Children with cochlear implants showed deficits in storage and processing, similar in size to those at second grade. Predictors of verbal working memory differed across groups: Phonological awareness explained the most variance in children with normal hearing; vocabulary explained the most variance in children with cochlear implants. Treatment variables explained little of the variance. Where potentially dependent functions were concerned, verbal working memory accounted for little variance once the variance explained by other predictors was removed. Conclusions The verbal working memory deficits of children with cochlear implants arise due to signal degradation, which limits their abilities to acquire phonological awareness. That hinders their abilities to store items using a phonological code.

Evaluating Pediatric Cochlear Implant Users' Encoding, Storage, and Retrieval Strategies in Verbal Working Memory

“…The latter findings suggested that encoding may contribute to pediatric CI users' individual differences in short-term and working memory, supplementing an earlier discovery that processing operations during storage were related to span (Pisoni & Cleary, 2003). Additional findings implicating CI users' vocabulary knowledge as the primary predictor for word span also suggested a role for retrieval mechanisms (Nittrouer et al, 2017). These previous results led us to test whether individual variation in memory span performance was better accounted for by measures related to processing operations during encoding and retrieval-such as recoding speed and vocabulary knowledge-or measures related to storage, such as nonword repetition.…”

“…Computational models of short-term memory demonstrate that larger vocabularies support redintegration processes by providing fast access to many possible lexical templates (Gupta & Tisdale, 2009). Indeed, pediatric CI users' vocabulary knowledge has been found to predict their performance on a word span task (Nittrouer et al, 2017). Redintegration processes also depend on stimulus characteristics.…”

“…Identifying the precise nature of pediatric CI users' shortterm and working memory deficits could lead to a better understanding of factors related to long-term speech, language, and literacy outcomes, which show considerable variability and individual differences in the CI population (Geers, Strube, Tobey, Pisoni, & Moog, 2011;Niparko et al, 2010). One line of research examining CI users' short-term and working memory deficits has focused on phonological storage (e.g., Nittrouer, Caldwell-Tarr, Low, & Lowenstein, 2017). Storage represents only the second of three stages of memory: encoding, storage, and retrieval.…”

The Role of Statistical Learning in Understanding and Treating Spoken Language Outcomes in Deaf Children With Cochlear Implants

“…On the one hand, we agree that it is likely that children with CIs may have an especially difficult time encoding and representing stimuli that lend themselves well to verbal rehearsal (Cleary et al, 2001;Gremp, 2011;Nittrouer, Caldwell-Tarr, Low, & Lowenstein, 2017), and so perhaps this is where the greatest group differences on SL tasks are likely to be found. On the other hand, there is some evidence that children with CIs show difficulty even with nonverbal sequencing tasks (e.g., .…”

Reasons for Language : Language and Analogical Reasoning Ability in Children with Cochlear Implants and Children with Typical Hearing

“…Therefore, they may be expected 1.3. Children with Cochlear Implants to perform more poorly compared to peers with TH, a finding observed in a number of studies (Akçakaya et al, 2019;Edwards et al, 2011;Nittrouer et al, 2017;Pixner et al, 2014). Language ability of importance for non-verbal cognitive measures that benefit from verbal strategies.…”