Assessment of Working Memory Capacity in Preschool Children Using the Missing Scan Task

The purpose of this study was to investigate the feasibility and validity of a modified version of Buschke's missing scan methodology, the Missing Scan Task (MST), to assess working memory capacity (WMC) and cognitive control processes in preschool children 3-6 years in age. Forty typically developing monolingual English-speaking children between 36 and 84 months in age participated in the study. The children were tested on measures of WMC (MST), verbal and nonverbal memory (NEPSY Narrative Memory and Memory for Designs subtests), and language skills (Peabody Picture Vocabulary Test, fourth edition). Children showed increased working memory capacity scores with age, as measured by the MST, with significant differences between 3- and 5-year-olds and 3- and 6-year-olds. Significant correlations were also found between the MST and language and verbal and nonverbal memory scores. MSTscores still remained significantly correlated with the other measures of memory even after age and global language were accounted for in a regression analysis, demonstrating that the MST captures unique variance related specifically to WMC and cognitive control processes used to retrieve and scan information in short-term memory (STM). The results of this study demonstrate that the MST is a feasible and valid methodology for assessing WMC in preschool children as young 3 years of age

Verbal Processing Speed and Executive Functioning in Long-Term Cochlear Implant Users

Purpose: The purpose of this study was to report how verbal rehearsal speed (VRS), a form of covert speech used to maintain verbal information in working memory, and another verbal processing speed measure, perceptual encoding speed, are related to 3 domains of executive function (EF) at risk in cochlear implant (CI) users: verbal working memory, fluency-speed, and inhibition-concentration. Method: EF, speech perception, and language outcome measures were obtained from 55 prelingually deaf, long-term CI users and matched controls with normal hearing (NH controls). Correlational analyses were used to assess relations between VRS (articulation rate), perceptual encoding speed (digit and color naming), and the outcomes in each sample. Results: CI users displayed slower verbal processing speeds than NH controls. Verbal rehearsal speed was related to 2 EF domains in the NH sample but was unrelated to EF outcomes in CI users. Perceptual encoding speed was related to all EF domains in both groups. Conclusions: Verbal rehearsal speed may be less influential for EF quality in CI users than for NH controls, whereas rapid automatized labeling skills and EF are closely related in both groups. CI users may develop processing strategies in EF tasks that differ from the covert speech strategies routinely employed by NH individuals

Long-term musical experience and auditory and visual perceptual abilities under adverse conditions

Musicians have been shown to have enhanced speech perception in noise skills. It is unclear whether these improvements are limited to the auditory modality, as no research has examined musicians' visual perceptual abilities under degraded conditions. The current study examined associations between long-term musical experience and visual perception under noisy or degraded conditions. The performance of 11 musicians and 11 age-matched nonmusicians was compared on several auditory and visual perceptions in noise measures. Auditory perception tests included speech-in-noise tests and an environmental sound in noise test. Visual perception tasks included a fragmented sentences task, an object recognition task, and a lip-reading measure. Participants' vocabulary knowledge and nonverbal reasoning abilities were also assessed. Musicians outperformed nonmusicians on the speech perception in noise measures as well as the visual fragmented sentences task. Musicians also displayed better vocabulary knowledge in comparison to nonmusicians. Associations were found between perception of speech and visually degraded text. The findings show that long-term musical experience is associated with modality-general improvements in perceptual abilities. Possible systems supporting musicians' perceptual abilities are discussed

Short-Term and Working Memory Impairments in Early-Implanted, Long-Term Cochlear Implant Users Are Independent of Audibility and Speech Production

OBJECTIVE: To determine whether early-implanted, long-term cochlear implant (CI) users display delays in verbal short-term and working memory capacity when processes related to audibility and speech production are eliminated. DESIGN: Twenty-three long-term CI users and 23 normal-hearing controls each completed forward and backward digit span tasks under testing conditions that differed in presentation modality (auditory or visual) and response output (spoken recall or manual pointing). RESULTS: Normal-hearing controls reproduced more lists of digits than the CI users, even when the test items were presented visually and the responses were made manually via touchscreen response. CONCLUSIONS: Short-term and working memory delays observed in CI users are not due to greater demands from peripheral sensory processes such as audibility or from overt speech-motor planning and response output organization. Instead, CI users are less efficient at encoding and maintaining phonological representations in verbal short-term memory using phonological and linguistic strategies during memory tasks

Visual-spatial sequence learning and memory in trained musicians

Previous research has shown that musicians have enhanced visual-spatial abilities and sensorymotor skills. As a result of their long-term musical training and their experience-dependent activities, musicians may learn to associate sensory information with fine motor movements. Playing a musical instrument requires musicians to rapidly translate musical symbols into specific sensory-motor actions while also simultaneously monitoring the auditory signals produced by their instrument. In this study, we assessed the visual-spatial sequence learning and memory abilities of long-term musicians. We recruited 24 highly trained musicians and 24 nonmusicians, individuals with little or no musical training experience. Participants completed a visual-spatial sequence learning task as well as receptive vocabulary, nonverbal reasoning, and short-term memory tasks. Results revealed that musicians have enhanced visual-spatial sequence learning abilities relative to nonmusicians. Musicians also performed better than nonmusicians on the vocabulary and nonverbal reasoning measures. Additional analyses revealed that the large group difference observed on the visualspatial sequencing task between musicians and nonmusicians remained even after controlling for vocabulary, nonverbal reasoning, and short-term memory abilities. Musicians' improved visualspatial sequence learning may stem from basic underlying differences in visual-spatial and sensorymotor skills resulting from long-term experience and activities associated with playing a musical instrument

Neurocognitive factors in sensory restoration of early deafness: a connectome model

Progress in biomedical technology (cochlear, vestibular, and retinal implants) has led to remarkable success in neurosensory restoration, particularly in the auditory system. However, outcomes vary considerably, even after accounting for comorbidity-for example, after cochlear implantation, some deaf children develop spoken language skills approaching those of their hearing peers, whereas other children fail to do so. Here, we review evidence that auditory deprivation has widespread effects on brain development, affecting the capacity to process information beyond the auditory system. After sensory loss and deafness, the brain's effective connectivity is altered within the auditory system, between sensory systems, and between the auditory system and centres serving higher order neurocognitive functions. As a result, congenital sensory loss could be thought of as a connectome disease, with interindividual variability in the brain's adaptation to sensory loss underpinning much of the observed variation in outcome of cochlear implantation. Different executive functions, sequential processing, and concept formation are at particular risk in deaf children. A battery of clinical tests can allow early identification of neurocognitive risk factors. Intervention strategies that address these impairments with a personalised approach, taking interindividual variations into account, will further improve outcomes

Executive functioning and speech-language skills following long-term use of cochlear implants

Neurocognitive processes such as executive functioning (EF) may influence the development of speech-language skills in deaf children after cochlear implantation in ways that differ from normal-hearing, typically developing children. Conversely, spoken language abilities and experiences may also exert reciprocal effects on the development of EF. The purpose of this study was to identify EF domains that are related to speech-language skills in cochlear implant (CI) users, compared to normal-hearing peers. Sixty-four prelingually deaf, early-implanted, long-term users of CIs and 74 normal-hearing peers equivalent in age and nonverbal intelligence completed measures of speech-language skills and three domains of EF: working memory, fluency-speed, and inhibition-concentration. Verbal working memory and fluency-speed were more strongly associated with speech-language outcomes in the CI users than in the normal-hearing peers. Spatial working memory and inhibition-concentration correlated positively with language skills in normal-hearing peers but not in CI users. The core domains of EF that are associated with spoken language development are different in long-term CI users compared to normal-hearing peers, suggesting important dissociations in neurocognitive development

Neurocognitive Risk in Children With Cochlear Implants

IMPORTANCE Children who receive a cochlear implant (CI) for early severe to profound sensorineural hearing loss may achieve age-appropriate spoken language skills not possible before implantation. Despite these advances, reduced access to auditory experience may have downstream effects on fundamental neurocognitive processes for some children with CIs. OBJECTIVE To determine the relative risk (RR) of clinically significant executive functioning deficits in children with CIs compared with children with normal hearing (NH). DESIGN, SETTING, AND PARTICIPANTS In this prospective, cross-sectional study, 73 children at a hospital-based clinic who received their CIs before 7 years of age and 78 children with NH, with average to above average mean nonverbal IQ scores, were recruited in 2 age groups: preschool age (age range, 3–5 years) and school age (age range, 7–17 years). No children presented with other developmental, cognitive, or neurologic diagnoses. INTERVENTIONS Parent-reported checklist measures of executive functioning were completed during psychological testing sessions. MAIN OUTCOMES AND MEASURES Estimates of the RR of clinically significant deficits in executive functioning (≥ 1 SDs above the mean) for children with CIs compared with children with NH were obtained based on 2 parent-reported child behavior checklists of everyday problems with executive functioning. RESULTS In most domains of executive functioning, children with CIs were at 2 to 5 times greater risk of clinically significant deficits compared with children with NH. The RRs for preschoolers and school-aged children, respectively, were greatest in the areas of comprehension and conceptual learning (RR [95% CI], 3.56 [1.71–7.43] and 6.25 [2.64–14.77]), factual memory ( 4.88 [1.58–15.07] and 5.47 [2.03–14.77]), attention (3.38 [1.03–11.04] and 3.13 [1.56–6.26]), sequential processing (11.25 [1.55–81.54] and 2.44 [1.24–4.76]), working memory (4.13 [1.30–13.06] and 3.64 [1.61–8.25] for one checklist and 1.77 [0.82–3.83] and 2.78 [1.18–6.51] for another checklist), and novel problem-solving (3.93 [1.50–10.34] and 3.13 [1.46–6.67]). No difference between the CI and NH samples was found for visual-spatial organization (2.63 [0.76–9.03] and 1.04 [0.45–2.40] on one checklist and 2.86 [0.98–8.39] for school-aged children on the other checklist). CONCLUSIONS AND RELEVANCE A large proportion of children with CIs are at risk for clinically significant deficits across multiple domains of executive functioning, a rate averaging 2 to 5 times that of children with NH for most domains. Screening for risk of executive functioning deficits should be a routine part of the clinical evaluation of all children with deafness and CIs

Executive Functioning Skills in Preschool-Age Children With Cochlear Implants

Purpose The purpose of this study was to determine whether deficits in executive functioning (EF) in children with cochlear implants (CIs) emerge as early as the preschool years. Method Two groups of children ages 3 to 6 years participated in this cross-sectional study: 24 preschoolers who had CIs prior to 36 months of age and 21 preschoolers with normal hearing (NH). All were tested on normed measures of working memory, inhibition-concentration, and organization-integration. Parents completed a normed rating scale of problem behaviors related to EF. Comparisons of EF skills of children with CIs were made to peers with NH and to published nationally representative norms. Results Preschoolers with CIs showed significantly poorer performance on inhibition-concentration and working memory compared with peers with NH and with national norms. No group differences were found in visual memory or organization-integration. When data were controlled for language, differences in performance measures of EF remained, whereas differences in parent-reported problems with EF were no longer significant. Hearing history was generally unrelated to EF. Conclusions This is the first study to demonstrate that EF deficits found in older children with CIs begin to emerge as early as preschool years. The ability to detect these deficits early has important implications for early intervention and habilitation after cochlear implantation