Effects of Age at Cochlear Implantation on Learning and Cognition: A Critical Assessment

Abstract

Purpose Age at cochlear implantation frequently is assumed to be a key predictor of pediatric implantation benefits, but outcomes related to learning and cognition appear inconsistent. This critical assessment examines relevant literature in an effort to evaluate the impact of age at implantation in those domains for individuals who received their devices as children. Method We examined 44 peer-reviewed articles from 2003 to 2018 considering age at implantation and conducted statistical analyses regarding its impact on several domains, including literacy, academic achievement, memory, and theory of mind. Results Across 167 assessments in various experiments and conditions, only 21% of the analyses related to age at implantation yielded evidence in favor of earlier implantation, providing greater benefits to academic achievement, learning, or cognition compared to implantation later in childhood. Among studies that considered cognitive processing (e.g., executive function, memory, visual–spatial functioning), over twice as many analyses indicated significant benefits of earlier implantation when it was considered as a discrete rather than a continuous variable. Conclusion Findings raise methodological, practical, and theoretical questions concerning how “early” is defined in studies concerning early cochlear implantation, the impact of confounding factors, and the use of nonstandard outcome measures. The present results and convergent findings from other studies are discussed in terms of the larger range of variables that need to be considered in evaluating the benefits of cochlear implantation and question the utility of considering age at implantation as a “gold standard” with regard to evaluating long-term outcomes of the procedure as a medical treatment/intervention for hearing loss. Supplemental Material https://doi.org/10.23641/asha.8323625

Children with hearing impairment and early cochlear implant: A pragmatic assessment

“…This result suggests that since the difference in performance is greater in younger children (7-year-olds), it seems to decrease as age increases. A possible explanation for this result is the major exposure, in terms of time, to the auditory stimuli experienced by older children (see Duchesne and Marschark, 2019;Marschark et al, 2019).…”

Cochlear Implants and Classroom Learning among Deaf College Students

“…Previous studies of academic achievement among CI users have demonstrated significant benefits among primary school-aged children, but those benefits consistently have been found attenuated or absent among CI users in secondary and postsecondary education Convertino et al [4,10,12,13,24,26]. Among those studies that included consideration of age of implantation Crowe et al [12,13,24] none found significant effects of age of implantation among older CI users Marschark et al [15]. Tests typically used in such studies assess current abilities in targeted domains such as reading or mathematics.…”

“…That is, although deaf children immersed early on in sign language environments have been found to demonstrate better reading achievement during the primary school years relative to deaf children who are not, the benefits of early sign language appear to be reduced or absent by high school and college age. Crowe et al [5,14,15,24,[26][27][28][29], suggested several possible explanations for such findings. Specifically, with regard to CI users, Archbold [5] noted that the materials and goals of reading at the secondary school level are very different than those at the primary school level.…”

“…Specifically, with regard to CI users, Archbold [5] noted that the materials and goals of reading at the secondary school level are very different than those at the primary school level. Addressing both populations of deaf learners, Marschark et al [15] additionally noted that the language used at the primary school level (e.g., basic interpersonal communication skills) are very different than those needed at the secondary school level (e.g., cognitive-academic language proficiency). Unfortunately, at least in the United States, deaf children who demonstrate grade-level appropriate language and academic skills at the primary levelfrequently including young CI users and native signers-typically lose their academic support services as they move into secondary education.…”

Theory of Mind Development in Deaf Children With Cochlear Implants: Literature Review

“…Current research on deaf children who use CIs has extended beyond functional communication, as improved language acquisition can also affect social development and ToM abilities [65]. In order to fully understand the relationship between cochlear implantation and ToM, different types of predictors should be included in the studies: age at implantation, level of specific language abilities, and family factors, including the quality of parental conversational input and the parents' perceptions of their child's social functioning.…”