Simon-Dack S L, Teder-Sälejärvi W A
North Dakota State University, Fargo, North Dakota, USA.
Brain Res. 2008 Jul 18;1220:171-8. doi: 10.1016/j.brainres.2007.09.015. Epub 2007 Sep 19.
Multisensory integration and interaction occur when bimodal stimuli are presented as either spatially congruent or incongruent, but temporally coincident. We investigated whether proprioceptive cues interact with auditory attention to one of two sound sources in free-field. The participant's task was to attend to either the left or right speaker and to respond to occasional increased-bandwidth targets via a footswitch. We recorded high-density EEG in three experimental conditions: the participants either held the speakers in their hands (Hold), reached out close to them (Reach), or had their hands in their lap (Lap). In the last two conditions, the auditory event-related potentials (ERPs) revealed a prominent negativity around 200 ms post-stimulus (N2 wave) over fronto-central areas, which is a reliable index of further processing of spatial stimulus features in free-field. The N2 wave was markedly attenuated in the 'Hold' condition, which suggests that proprioceptive cues apparently solidify spatial information computed by the auditory system, in so doing alleviating the need for further processing of spatial coordinates solely based on auditory information.
当双峰刺激在空间上一致或不一致但时间上重合时，就会发生多感官整合与交互。我们研究了本体感觉线索是否会与对自由场中两个声源之一的听觉注意力相互作用。参与者的任务是关注左扬声器或右扬声器，并通过脚踏开关对偶尔出现的带宽增加的目标做出反应。我们在三种实验条件下记录了高密度脑电图：参与者要么将扬声器握在手中（握持），要么伸手靠近它们（伸手），要么双手放在腿上（腿上）。在后两种条件下，听觉事件相关电位（ERP）在刺激后约200毫秒在额中央区域显示出明显的负性（N2波），这是自由场中空间刺激特征进一步处理的可靠指标。在“握持”条件下，N2波明显减弱，这表明本体感觉线索显然巩固了听觉系统计算出的空间信息，从而减少了仅基于听觉信息对空间坐标进行进一步处理的需求。
