Institute of Physics, School of Natural Sciences, Chemnitz University of Technology, Reichenhainer Str. 70, D-09126, Chemnitz, Germany; Auditory Psychophysiology Lab, Department of Psychology, Carl von Ossietzky University of Oldenburg, Ammerländer Heerstr. 114-118, D-26129, Oldenburg, Germany.
Institute of Physics, School of Natural Sciences, Chemnitz University of Technology, Reichenhainer Str. 70, D-09126, Chemnitz, Germany; Institute of Psychology, University of Leipzig, Neumarkt 9-19, D-04109, Leipzig, Germany.
Hear Res. 2018 Dec;370:120-129. doi: 10.1016/j.heares.2018.09.008. Epub 2018 Oct 3.
A listener who focusses on a sound source of interest must continuously integrate the sounds emitted by the attended source and ignore the sounds emitted by the remaining sources in the auditory scene. Little is known about how the ignored sound sources in the background are mentally represented after the source of interest has formed the perceptual foreground. This is due to a key methodological challenge: the background representation is by definition not overtly reportable. Here we developed a paradigm based on event-related brain potentials (ERPs) to assess the mental representation of background sounds. Participants listened to sequences of three repeatedly presented tones arranged in an ascending order (low, middle, high frequency). They were instructed to detect intensity deviants in one of the tones, creating the perceptual foreground. The remaining two background tones contained timing and location deviants. Those deviants were set up such that mismatch negativity (MMN) components would be elicited in distinct ways if the background was decomposed into two separate sound streams (background segregation) or if it was not further decomposed (background integration). Results provide MMN-based evidence for background segregation and integration in parallel. This suggests that mental representations of background integration and segregation can be concurrently available, and that collecting empirical evidence for only one of these background organization alternatives might lead to erroneous conclusions.
听众必须不断地将注意力集中在感兴趣的声源上，同时将听觉场景中其余声源发出的声音整合起来。目前对于在目标声源形成感知前景后，背景中被忽略的声源在心理上是如何被表示的，人们知之甚少。这是由于一个关键的方法学挑战：背景表示从定义上讲是无法明确报告的。在这里，我们开发了一种基于事件相关脑电位（ERPs）的范式来评估背景声音的心理表示。参与者听三个重复呈现的音调组成的序列，这些音调按升序排列（低频、中频、高频）。他们被指示在其中一个音调中检测强度偏差，从而形成感知前景。其余两个背景音包含时间和位置偏差。这些偏差的设置方式是，如果将背景分解为两个单独的音流（背景分离），或者如果不进一步分解（背景整合），则会以不同的方式引出失匹配负波（MMN）成分。结果提供了基于 MMN 的背景分离和整合的并行证据。这表明背景整合和分离的心理表示可以同时存在，并且仅收集其中一种背景组织替代方案的经验证据可能会导致错误的结论。
