Faculty of Life Science, University of Manchester, Manchester M13 9PL, UK.
Faculty of Life Science, University of Manchester, Manchester M13 9PL, UK.
Hear Res. 2014 Jun;312(100):91-102. doi: 10.1016/j.heares.2014.03.006. Epub 2014 Apr 1.
Todd et al. (2014) have recently demonstrated the presence of vestibular dependent changes both in the morphology and in the intensity dependence of auditory evoked potentials (AEPs) when passing through the vestibular threshold as determined by vestibular evoked myogenic potentials (VEMPs). In this paper we extend this work by comparing left vs. right ear stimulation and by conducting a source analysis of the resulting evoked potentials of short and long latency. Ten healthy, right-handed subjects were recruited and evoked potentials were recorded to both left- and right-ear sound stimulation, above and below vestibular threshold. Below VEMP threshold, typical AEPs were recorded, consisting of mid-latency (MLR) waves Na and Pa followed by long latency AEPs (LAEPs) N1 and P2. In the supra-threshold condition, the expected changes in morphology were observed, consisting of: (1) short-latency vestibular evoked potentials (VsEPs) which have no auditory correlate, i.e. the ocular VEMP (OVEMP) and inion response related potentials; (2) a later deflection, labelled N42/P52, followed by the LAEPs N1 and P2. Statistical analysis of the vestibular dependent responses indicated a contralateral effect for inion related short-latency responses and a left-ear/right-hemisphere advantage for the long-latency responses. Source analysis indicated that the short-latency effects may be mediated by a contralateral projection to left cerebellum, while the long-latency effects were mediated by a contralateral projection to right cingulate cortex. In addition we found evidence of a possible vestibular contribution to the auditory T-complex in radial temporal lobe sources. These last results raise the possibility that acoustic activation of the otolith organs could potentially contribute to auditory processing.
托德等人（2014 年）最近通过前庭诱发肌源性电位（VEMPs）确定的前庭阈值，证明了听觉诱发电位（AEPs）的形态和强度依赖性方面存在前庭依赖性变化。在本文中，我们通过比较左耳和右耳刺激来扩展这项工作，并对短潜伏期和长潜伏期的诱发电位进行源分析。我们招募了 10 名健康的右利手受试者，对左耳和右耳的声音刺激进行了诱发电位记录，刺激强度高于和低于前庭阈值。在 VEMP 阈值以下，记录到了典型的 AEP，包括中潜伏期（MLR）波 Na 和 Pa，随后是长潜伏期 AEP（LAEP）N1 和 P2。在阈上条件下，观察到了形态的预期变化，包括：（1）没有听觉相关性的短潜伏期前庭诱发电位（VsEPs），即眼动前庭诱发电位（OVEMP）和顶骨相关的潜在反应；（2）较晚的偏转，标记为 N42/P52，随后是 LAEP N1 和 P2。对前庭依赖性反应的统计分析表明，顶骨相关的短潜伏期反应存在对侧效应，而长潜伏期反应存在左耳/右脑半球优势。源分析表明，短潜伏期效应可能是由左侧小脑的对侧投射介导的，而长潜伏期效应则是由右侧扣带回皮层的对侧投射介导的。此外，我们发现了前庭对放射状颞叶源听觉 T 复合体可能有贡献的证据。这些最后的结果提出了一种可能性，即耳石器官的声学激活可能有助于听觉处理。
