Winkler István, van Zuijen Titia L, Sussman Elyse, Horváth János, Näätänen Risto
Institute for Psychology, Hungarian Academy of Sciences, H-1394 Budapest, P.O.Box 398, Hungary.
Eur J Neurosci. 2006 Jul;24(2):625-34. doi: 10.1111/j.1460-9568.2006.04925.x. Epub 2006 Jul 12.
One important principle of object processing is exclusive allocation. Any part of the sensory input, including the border between two objects, can only belong to one object at a time. We tested whether tones forming a spectro-temporal border between two sound patterns can belong to both patterns at the same time. Sequences were composed of low-, intermediate- and high-pitched tones. Tones were delivered with short onset-to-onset intervals causing the high and low tones to automatically form separate low and high sound streams. The intermediate-pitch tones could be perceived as part of either one or the other stream, but not both streams at the same time. Thus these tones formed a pitch 'border' between the two streams. The tones were presented in a fixed, cyclically repeating order. Linking the intermediate-pitch tones with the high or the low tones resulted in the perception of two different repeating tonal patterns. Participants were instructed to maintain perception of one of the two tone patterns throughout the stimulus sequences. Occasional changes violated either the selected or the alternative tone pattern, but not both at the same time. We found that only violations of the selected pattern elicited the mismatch negativity event-related potential, indicating that only this pattern was represented in the auditory system. This result suggests that individual sounds are processed as part of only one auditory pattern at a time. Thus tones forming a spectro-temporal border are exclusively assigned to one sound object at any given time, as are spatio-temporal borders in vision.
客体加工的一个重要原则是排他性分配。感觉输入的任何部分，包括两个客体之间的边界，在同一时间只能属于一个客体。我们测试了在两种声音模式之间形成频谱-时间边界的音调是否能同时属于这两种模式。序列由低音调、中音调及高音调的音调组成。音调以短的起始间隔呈现，使得高音调和低音调自动形成分离的低声流和高声流。中音调的音调可以被感知为其中一个或另一个声流的一部分，但不能同时被感知为两个声流的一部分。因此，这些音调在两个声流之间形成了一个音高“边界”。音调以固定的、循环重复的顺序呈现。将中音调的音调与高音调或低音调联系起来会导致对两种不同的重复音调模式的感知。参与者被要求在整个刺激序列中保持对两种音调模式之一的感知。偶尔的变化会违反所选的或另一种音调模式，但不会同时违反两者。我们发现只有违反所选模式才会引发失配负波事件相关电位，这表明只有这种模式在听觉系统中得到了表征。这一结果表明，单个声音在同一时间仅作为一种听觉模式的一部分进行加工。因此，在任何给定时间，形成频谱-时间边界的音调都被排他性地分配给一个声音客体，视觉中的时空边界也是如此。
