Glick Hannah, Sharma Anu
Department of Speech, Language, & Hearing Science; Institute of Cognitive Science, University of Colorado at Boulder, 2501 Kittredge Loop Road, 409 UCB, Boulder, CO 80309, USA.
Department of Speech, Language, & Hearing Science; Institute of Cognitive Science, University of Colorado at Boulder, 2501 Kittredge Loop Road, 409 UCB, Boulder, CO 80309, USA.
Hear Res. 2017 Jan;343:191-201. doi: 10.1016/j.heares.2016.08.012. Epub 2016 Sep 6.
This review explores cross-modal cortical plasticity as a result of auditory deprivation in populations with hearing loss across the age spectrum, from development to adulthood. Cross-modal plasticity refers to the phenomenon when deprivation in one sensory modality (e.g. the auditory modality as in deafness or hearing loss) results in the recruitment of cortical resources of the deprived modality by intact sensory modalities (e.g. visual or somatosensory systems). We discuss recruitment of auditory cortical resources for visual and somatosensory processing in deafness and in lesser degrees of hearing loss. We describe developmental cross-modal re-organization in the context of congenital or pre-lingual deafness in childhood and in the context of adult-onset, age-related hearing loss, with a focus on how cross-modal plasticity relates to clinical outcomes. We provide both single-subject and group-level evidence of cross-modal re-organization by the visual and somatosensory systems in bilateral, congenital deafness, single-sided deafness, adults with early-stage, mild-moderate hearing loss, and individual adult and pediatric patients exhibit excellent and average speech perception with hearing aids and cochlear implants. We discuss a framework in which changes in cortical resource allocation secondary to hearing loss results in decreased intra-modal plasticity in auditory cortex, accompanied by increased cross-modal recruitment of auditory cortices by the other sensory systems, and simultaneous compensatory activation of frontal cortices. The frontal cortices, as we will discuss, play an important role in mediating cognitive compensation in hearing loss. Given the wide range of variability in behavioral performance following audiological intervention, changes in cortical plasticity may play a valuable role in the prediction of clinical outcomes following intervention. Further, the development of new technologies and rehabilitation strategies that incorporate brain-based biomarkers may help better serve hearing impaired populations across the lifespan.
本综述探讨了从发育到成年的各年龄段听力损失人群中，因听觉剥夺导致的跨模态皮质可塑性。跨模态可塑性是指当一种感觉模态（如耳聋或听力损失中的听觉模态）被剥夺时，由完整的感觉模态（如视觉或体感系统）募集被剥夺模态的皮质资源的现象。我们讨论了在耳聋和较轻程度听力损失中，视觉和体感处理对听觉皮质资源的募集情况。我们描述了儿童先天性或语前聋以及成人迟发性、年龄相关性听力损失背景下的发育性跨模态重组，重点关注跨模态可塑性与临床结果的关系。我们提供了单病例和群体水平的证据，证明了双侧先天性耳聋、单侧耳聋、早期轻度至中度听力损失的成年人以及个别成人和儿童患者的视觉和体感系统在跨模态重组方面的情况，这些患者在使用助听器和人工耳蜗时表现出良好和中等的言语感知能力。我们讨论了一个框架，其中听力损失继发的皮质资源分配变化导致听觉皮质内模态可塑性降低，同时其他感觉系统对听觉皮质的跨模态募集增加，以及额叶皮质的同时代偿性激活。正如我们将讨论的，额叶皮质在介导听力损失的认知代偿中起着重要作用。鉴于听力干预后行为表现存在广泛的变异性，皮质可塑性的变化可能在预测干预后的临床结果中发挥重要作用。此外，结合基于脑的生物标志物的新技术和康复策略的发展，可能有助于更好地为全生命周期的听力受损人群服务。
