Independent mechanisms for ventriloquism and multisensory integration as revealed by theta-burst stimulation
Independent mechanisms for ventriloquism and multisensory integration as revealed by theta-burst stimulation
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DOI：
10.1111/j.1460-9568.2010.07200.x
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发表时间：
2010-05-01
影响因子：
3.4
通讯作者：
Ladavas, Elisabetta
中科院分区：
文献类型：
--
作者：
Bertini, Caterina;Leo, Fabrizio;Ladavas, Elisabetta
视觉系统和听觉系统通常同时产生统一的感知体验，并确定外部世界中物体的位置。已知在空间重合中同时出现的听觉和视觉刺激由于来自不同感觉通道的刺激的整合（即多感觉整合）而增强听觉定位的性能。然而，在空间差异的视听刺激的听觉定位也可能会导致对视觉刺激的声音的错误定位（即口技效应）。使用重复的经颅磁刺激，我们测试的作用，右颞顶（rTPC），右枕（rOC）和右后顶叶（rPPC）皮质在听觉定位任务中的腹语和多感觉统合的指数进行了计算。我们发现，抑制rTPC的兴奋性，通过连续θ-爆发刺激（cTBS）减少多感觉整合。没有发现cTBS对rOC有类似的影响。此外，抑制rOC，而不是rTPC，抑制对侧半野的视觉偏差。相比之下，cTBS对rPPC没有产生任何调节腹语或整合效应。在本研究中发现的双重分离表明，腹语和视听多感觉整合是功能独立的现象，可能是由部分不同的神经回路。
The visual and auditory systems often concur to create a unified perceptual experience and to determine the localization of objects in the external world. Co-occurring auditory and visual stimuli in spatial coincidence are known to enhance performance of auditory localization due to the integration of stimuli from different sensory channels (i.e. multisensory integration). However, auditory localization of audiovisual stimuli presented at spatial disparity might also induce a mislocalization of the sound towards the visual stimulus (i.e. ventriloquism effect). Using repetitive transcranial magnetic stimulation we tested the role of right temporoparietal (rTPC), right occipital (rOC) and right posterior parietal (rPPC) cortex in an auditory localization task in which indices of ventriloquism and multisensory integration were computed. We found that suppression of rTPC excitability by means of continuous theta-burst stimulation (cTBS) reduced multisensory integration. No similar effect was found for cTBS over rOC. Moreover, inhibition of rOC, but not of rTPC, suppressed the visual bias in the contralateral hemifield. In contrast, cTBS over rPPC did not produce any modulation of ventriloquism or integrative effects. The double dissociation found in the present study suggests that ventriloquism and audiovisual multisensory integration are functionally independent phenomena and may be underpinned by partially different neural circuits.