Menning Hans, Ackermann Hermann, Hertrich Ingo, Mathiak Klaus
MEG Center, Center for Neurology, University of Tübingen, Otfried-Müller-Str. 47, 72076, Tübingen, Germany.
Exp Brain Res. 2005 Jul;164(1):41-7. doi: 10.1007/s00221-004-2212-7. Epub 2005 Feb 23.
Previous studies have shown that cross-modal processing affects perception at a variety of neuronal levels. In this study, event-related brain responses were recorded via whole-head magnetoencephalography (MEG). Spatial auditory attention was directed via tactile pre-cues (primes) to one of four locations in the peripersonal space (left and right hand versus face). Auditory stimuli were white noise bursts, convoluted with head-related transfer functions, which ensured spatial perception of the four locations. Tactile primes (200-300 ms prior to acoustic onset) were applied randomly to one of these locations. Attentional load was controlled by three different visual distraction tasks. The auditory P50m (about 50 ms after stimulus onset) showed a significant "proximity" effect (larger responses to face stimulation as well as a "contralaterality" effect between side of stimulation and hemisphere). The tactile primes essentially reduced both the P50m and N100m components. However, facial tactile pre-stimulation yielded an enhanced ipsilateral N100m. These results show that earlier responses are mainly governed by exogenous stimulus properties whereas cross-sensory interaction is spatially selective at a later (endogenous) processing stage.
先前的研究表明，跨模态加工在多种神经元水平上影响感知。在本研究中，通过全头式脑磁图（MEG）记录事件相关脑反应。通过触觉预线索（启动刺激）将空间听觉注意力引导至个人周围空间的四个位置之一（左手、右手与面部）。听觉刺激为白噪声脉冲，与头部相关传递函数进行卷积，以确保对四个位置的空间感知。触觉启动刺激（在声音开始前200 - 300毫秒）随机应用于这些位置之一。通过三种不同的视觉分心任务控制注意力负荷。听觉P50m（刺激开始后约50毫秒）显示出显著的“接近”效应（对面部刺激的反应更大）以及刺激侧与半球之间的“对侧性”效应。触觉启动刺激基本上降低了P50m和N100m成分。然而，面部触觉预刺激产生了增强的同侧N100m。这些结果表明，早期反应主要由外源性刺激特性决定，而跨感觉相互作用在后期（内源性）加工阶段具有空间选择性。
