Verbal Information-processing Capabilities and Cochlear Implants: Implications for Preoperative Predictors of Speech Understanding

Abstract

In this study, we examined preoperative verbal cognitive capacity in 11 deafened adults who were cochlear implant candidates and reexamined level of speech understanding after 6-8 months' experience with the implant. Verbal cognitive performance in the implant group was compared in a group of normal hearing subjects and in nonimplanted group of deafened adults. The three groups performed on par with each other with an exception: The individuals in the cochlear implant group and the nonimplanted group of deafened adults performed significatly worse than those of normal hearing in tasks in which use of internal speech is a key feature (i.e., rhyme judgement and lexical decision tasks). Postoperative observations of the implanted individuals' level of speech understanding suggest that it is possible to predict the level of speech understanding by means of a properative cognitive assessment. The characteristics of three verbal cognitive abilities prove to be critical indicators of 6 - 8 months' postoperative outcome: internal speech functioning, speed of verval information processing, and working memory capacity - the first factor proved the most decisive. We discuss the results with respect to direct versus indirect predictors of outcomes from cochlear implant operations and the effect of auditory deprivation on deafened adults' capability to process auditory information.

Cognitive Predictors of Improvements in Adults’ Spoken Word Recognition Six Months after Cochlear Implant Activation

“…It has been reported, however, that a visual monitoring task that requires rapid processing of sequential signals is related to spoken word recognition [Gantz et al, 1993;Knutson et al, 1991]. In addition, Lyxell et al [1996] found that processing speed and WM measured prior to surgery predicted speech recognition ability after implantation, and Kropp et al [2000] reported that general intellectual capacity, visual memory and nonverbal reasoning in adult CI recipients were correlated with the ability to perceive spoken numbers but not open-set words or sentences. Thus, the evidence to date from behavioral research concerning which cognitive abilities affect CI outcome in adult recipients is mixed, and it is as yet unclear whether just a few basic, domain-specific cognitive functions are important or whether individual differences in general intellectual ability underlie the variability in outcomes.…”

Some Measures of Verbal and Spatial Working Memory in Eight- and Nine-Year-Old Hearing-Impaired Children with Cochlear Implants

“…Surprisingly, relatively little other research has focused directly on auditory working memory in users of cochlear implants. Lyxell, Andersson, Arlinger, Bredberg, Harder, and Ronnberg (1996) have, however, examined in adult cochlear implant users whether it might be "possible to predict the level of speech understanding (postimplant) by means of a preoperative cognitive assessment." Because Lyxell had previously obtained results suggesting that individual differences in processing speed and working memory capacity could account for a portion of the variability found in the speechreading/lipreading scores of normal-hearing adults, he hypothesized that this same relationship might also be observed in users of cochlear implants.…”

Cognitive capacities and composite cognitive skills in individuals with Usher syndrome type 1 and 2

“…The task is to correctly identify the pairs of antonyms among the five words of each item in five minutes. The test has been used repeatedly for the purpose of estimating level of verbal ability in participants in different projects (Lyxell et al, 1996;.…”

“…The test has been developed by Lyxell et al (1996) in accordance with cognitive theories on phonological processing. The task was to identify the pairs of words that rhymed, regardless of how the words were spelled or what font size was used.…”

“…The lexical test for adults has been developed by Lyxell et al (1996) in accordance with theories on lexical processing. The items were presented visually and the task was to push a button corresponding to 'yes' for the real words displayed, and 'no' when the item was not a word.…”