Rochester Institute of Technology, Rochester, NY, United States of America.
Department of Speech Language and Hearing Sciences, University of Colorado Boulder, Boulder, CO, United States of America.
Hear Res. 2024 Sep 15;451:109074. doi: 10.1016/j.heares.2024.109074. Epub 2024 Jul 3.
Many children with profound hearing loss have received cochlear implants (CI) to help restore some sense of hearing. There is, however, limited research on long-term neurocognitive outcomes in young adults who have grown up hearing through a CI. This study compared the cognitive outcomes of early-implanted (n = 20) and late-implanted (n = 21) young adult CI users, and typically hearing (TH) controls (n=56), all of whom were enrolled in college. Cognitive fluidity, nonverbal intelligence, and American Sign Language (ASL) comprehension were assessed, revealing no significant differences in cognition and nonverbal intelligence between the early and late-implanted groups. However, there was a difference in ASL comprehension, with the late-implanted group having significantly higher ASL comprehension. Although young adult CI users showed significantly lower scores in a working memory and processing speed task than TH age-matched controls, there were no significant differences in tasks involving executive function shifting, inhibitory control, and episodic memory between young adult CI and young adult TH participants. In an exploratory analysis of a subset of CI participants (n = 17) in whom we were able to examine crossmodal plasticity, we saw greater evidence of crossmodal recruitment from the visual system in late-implanted compared with early-implanted CI young adults. However, cortical visual evoked potential latency biomarkers of crossmodal plasticity were not correlated with cognitive measures or ASL comprehension. The results suggest that in the late-implanted CI users, early access to sign language may have served as a scaffold for appropriate cognitive development, while in the early-implanted group early access to oral language benefited cognitive development. Furthermore, our results suggest that the persistence of crossmodal neuroplasticity into adulthood does not necessarily impact cognitive development. In conclusion, early access to language - spoken or signed - may be important for cognitive development, with no observable effect of crossmodal plasticity on cognitive outcomes.
许多患有深度听力损失的儿童已经接受了人工耳蜗植入 (CI) 以帮助恢复部分听力。然而，对于通过 CI 听到声音而成长的年轻成年人的长期神经认知结果的研究有限。本研究比较了早期植入 (n = 20) 和晚期植入 (n = 21) 的年轻成人 CI 用户以及典型听力 (TH) 对照组 (n = 56) 的认知结果，所有这些人都在大学就读。评估了认知灵活性、非言语智力和美国手语 (ASL) 理解能力，结果表明早期和晚期植入组在认知和非言语智力方面没有显著差异。然而，在 ASL 理解方面存在差异，晚期植入组的 ASL 理解能力明显更高。尽管年轻成人 CI 用户在工作记忆和处理速度任务中的得分明显低于 TH 年龄匹配的对照组，但在执行功能转换、抑制控制和情景记忆任务中，年轻成人 CI 和 TH 参与者之间没有显著差异。在对能够检查跨模态可塑性的 CI 参与者子集 (n = 17) 的探索性分析中，我们发现晚期植入的 CI 年轻成年人比早期植入的 CI 年轻成年人的视觉系统中跨模态招募的证据更大。然而，跨模态可塑性的皮质视觉诱发电位潜伏期生物标志物与认知测量或 ASL 理解没有相关性。结果表明，在晚期植入的 CI 用户中，早期接触手语可能为适当的认知发展提供了支架，而在早期植入的组中，早期接触口语语言则有利于认知发展。此外，我们的结果表明，成年后跨模态神经可塑性的持续存在不一定会影响认知发展。总之，早期接触语言——口语或手语——可能对认知发展很重要，跨模态可塑性对认知结果没有明显影响。
