Exploring in Silence: Hearing and Deaf Infants Explore Objects Differently before Cochlear Implantation

Parent-child sensorimotor coordination in toddlers with and without hearing loss

Infants experience the world through their actions with objects and their interactions with other people, especially their parents. Prior research has shown that school-age children with hearing loss experience poorer quality interactions with typically hearing parents, yet little is known about parent-child interactions between toddlers with hearing loss and their parents early in life. In the current study, we used mobile eye-tracking to investigate parent-child interactions in toddlers with and without hearing loss (mean ages: 19.42 months, SD = 3.41 months). Parents and toddlers engaged in a goal-directed, interactive task that involved inserting coins into a slot and required joint coordination between the parent and the child. Overall, findings revealed that deaf toddlers demonstrate typical action skills in line with their hearing peers and engage in similar interactions with their parents during social interactions. Findings also revealed that deaf toddlers explored objects more and showed more temporal stability in their motor movements (i.e. less variation in their timing across trials) than hearing peers, suggesting further adaptability of the deaf group to their atypical sensory environment rather than poorer coordination. In contrast to previous research, findings suggest an intact ability of deaf toddlers to coordinate their actions with their parents and highlight the adaptability within dyads who have atypical sensory experiences.

Comparative executive function analysis: Cochlear implants and normal hearing in 7- to 11-year-old children from Iran

OBJECTIVE

This study compares executive functioning in deaf children with cochlear implants and those with normal hearing. Individuals who lacked auditory stimulation during their early years might experience cognitive challenges that extend beyond just speech and language abilities.

METHODS

The executive functioning abilities of a group of 32 children who were born deaf and received cochlear implants before the age of 7 were contrasted with those of 30 children with normal hearing. Both sets of children underwent assessments using the Tower of London, BRIEF, and Stroop tests.

RESULTS

The average score on the Tower of London task reveals that children who received cochlear implants (4.03 ± 2.53) achieved lower scores than typically hearing children (8.37 ± 2.79). This group also exhibited higher errors in the Stroop test and slightly longer response times Additionally, in terms of emotional control assessed by the BRIEF, a higher score was recorded. Notably, significant differences between the two groups were identified for organizing materials (t(62) = -4.204, p = 0.00). The tests measuring phonemic fluency, categorical fluency, and working memory also revealed significant differences.

CONCLUSIONS

The significant differences in data between both groups suggest the influence of cochlear implantation on cognitive functions. This emphasizes the importance of a holistic approach to supporting the overall development of these children.

Prelinguistic Consonant Production and the Influence of Mouthing Before and After Cochlear Implantation

OBJECTIVES

The goal of the study was to investigate prelinguistic consonant production and the influence of vocalizations that co-occurred with object mouthing on consonant production in infants with profound sensorineural hearing loss before and after cochlear implantation to advance knowledge of early speech development in infants with profound hearing loss.

DESIGN

Participants were 43 infants, 16 infants with profound sensorineural hearing loss and 27 hearing infants. In the mixed longitudinal and cross-sectional design, infants with profound hearing loss and age-matched hearing infants participated before cochlear implantation, at an average age of 9.9 mo, and/or after cochlear implantation, at an average age of 17.8 mo. Mean age at cochlear implantation for infants with profound hearing loss was 12.4 mo; mean duration of cochlear implant use at time of testing was 4.2 mo.

RESULTS

Before and after cochlear implantation, infants with profound hearing loss produced significantly fewer supraglottal consonants per consonant-vowel vocalization than hearing peers and had smaller overall consonant inventories. Before, but not after cochlear implantation, infants with profound hearing loss produced proportionally more vocalizations, supraglottal consonant-vowel vocalizations, and different supraglottal consonants in vocalizations during mouthing than did hearing infants.

CONCLUSIONS

The results document consonant production before cochlear implantation in a larger group of infants with profound hearing loss than previously examined. The results also extend evidence of early delays in consonant production to infants who received cochlear implants at 12 mo of age, and show that they likely miss the potential benefits of auditory-motor feedback in vocalization-mouthing combinations that occur before they have access to sound through cochlear implants.

Longitudinal Development of Executive Functioning and Spoken Language Skills in Preschool-Aged Children With Cochlear Implants

Purpose Auditory deprivation has downstream effects on the development of language and executive functioning (EF) in prelingually deaf children with cochlear implants (CIs), but little is known about the very early development of EF during preschool ages in children with CIs. This study investigated the longitudinal development of EF and spoken language skills in samples of children with normal hearing (NH; N = 40) or CIs (N = 41) during preschool ages. Method Participants were enrolled in the study between ages 3 and 6 years and evaluated annually up to the age of 7 years. Mixed-effects models were used to evaluate and predict growth of spoken language and EF skills over time. Results Children with CIs scored lower than NH peers on language measures but improved significantly over time. On performance-based neurocognitive measures of controlled attention, inhibition, and working memory, children with CIs scored more poorly than the sample of NH peers but comparable to norms, whereas on a parent report behavior checklist, children with CIs scored more poorly than both NH peers and norms on inhibition and working memory. Children with CIs had poorer EF than the sample of NH peers in most domains even after accounting for language effects, and language predicted only the verbal working memory domain of EF. In contrast, EF skills consistently predicted language skills at subsequent visits. Conclusions Findings demonstrate that, despite significant improvement over time, some domains of EF (particularly parent-reported EF) and language skills in children with CIs lag behind those of children with NH during preschool ages. Language delays do not fully explain differences in EF development between children with CIs and NH peers during preschool ages, but EF skills predict subsequent language development in children with CIs.

What Mothers Do After Infants Vocalize: Implications for Vocal Development or Word Learning?

Purpose The goal of this study was to analyze verbal and nonverbal maternal response types following infant vocalizations in younger (ages 4-8 months) versus older (ages 10-14 months) infant groups and their potential implications for infant vocal development or word learning. Method Maternal response types that occurred within 3 s of infant vocalizations were examined in this cross-sectional study of naturalistic interactions in 35 mother-infant dyads. Response types were defined as vocally responsive to infant vocalizations (i.e., responsive vocal behaviors), not responsive to infant vocalizations directly (nonresponsive vocal behaviors), and silences. Mothers' nonverbal actions associated with each response type were also examined. Subcategories of these verbal and nonverbal response types were examined in relation to infant age group. Results The occurrence of responsive and nonresponsive verbal subcategory types differed by infant age group. When verbally responsive to infant vocalizations, mothers commented on younger infants' vowel and consonant-vowel vocalizations, but with older infants, mothers identified or named the referents of their vocalizations. When nonresponsive to vocalizations directly, mothers commented on younger infants' activities but redirected older infants' behaviors or commented on their movements. Silence after infant vocalizations was infrequent. Mothers' nonverbal actions associated with each response type were primarily object related and did not differ by age group. Conclusions Evaluating response type subcategories by age group indicated mothers did not respond differentially (verbally or nonverbally) to vowel or consonant-vowel vocalizations. Overall, the results suggest mothers' verbal and nonverbal response types may be more likely to facilitate word learning than vocal development.