Rahne Torsten, Böckmann Martin, von Specht Hellmut, Sussman Elyse S
Department of Experimental Audiology and Medical Physics, Otto-von-Guericke-University Magdeburg, Germany.
Brain Res. 2007 May 4;1144:127-35. doi: 10.1016/j.brainres.2007.01.074. Epub 2007 Jan 27.
The task of assigning concurrent sounds to different auditory objects is known to depend on temporal and spectral cues. When tones of high and low frequencies are presented in alternation, they can be perceived as a single, integrated melody, or as two parallel, segregated melodic lines, according to the presentation rate and frequency distance between the sounds. At an intermediate distance, in the 'ambiguous' range, both percepts are possible. We conducted an electrophysiological experiment to determine whether an ambiguous sound organization could be modulated toward an integrated or segregated percept by the synchronous presentation of visual cues. Two sets of sounds (one high frequency and one low frequency) were interleaved. To promote integration or segregation, visual stimuli were synchronized to either the within-set frequency pattern or to the across-set intensity pattern. Elicitation of the mismatch negativity (MMN) component of event-related brain potentials was used to index the segregated organization, when no task was performed with the sounds. MMN was elicited only when the visual pattern promoted the segregation of the sounds. The results demonstrate cross-modal effects on auditory object perception in that sound ambiguity was resolved by synchronous presentation of visual stimuli, which promoted either an integrated or segregated perception of the sounds.
已知将同时出现的声音分配到不同听觉对象的任务取决于时间和频谱线索。当高低频音调交替呈现时，根据声音之间的呈现速率和频率距离，它们可以被感知为单一的、整合的旋律，或者两条平行的、分离的旋律线。在中间距离，即在“模糊”范围内，两种感知都是可能的。我们进行了一项电生理实验，以确定通过视觉线索的同步呈现，模糊的声音组织是否可以被调节为整合或分离的感知。两组声音（一组高频和一组低频）交错出现。为了促进整合或分离，视觉刺激与组内频率模式或组间强度模式同步。当不对声音执行任何任务时，使用事件相关脑电位的失配负波（MMN）成分来索引分离的组织。仅当视觉模式促进声音分离时才会诱发MMN。结果表明，视觉刺激的同步呈现解决了声音的模糊性，促进了对声音的整合或分离感知，从而证明了跨模态对听觉对象感知的影响。
