Data from: An auditory illusion reveals the role of streaming in the temporal misallocation of perceptual objects

This study investigates the neural correlates and processes underlying the ambiguous percept produced by a stimulus similar to Deutsch's ‘octave illusion’, in which each ear is presented with a sequence of alternating pure tones of low and high frequencies. The same sequence is presented to each ear, but in opposite phase, such that the left and right ears receive a high–low–high … and a low–high–low … pattern, respectively. Listeners generally report hearing the illusion of an alternating pattern of low and high tones, with all the low tones lateralized to one side and all the high tones lateralized to the other side. The current explanation of the illusion is that it reflects an illusory feature conjunction of pitch and perceived location. Using psychophysics and electroencephalogram measures, we test this and an alternative hypothesis involving synchronous and sequential stream segregation, and investigate potential neural correlates of the illusion. We find that the illusion of alternating tones arises from the synchronous tone pairs across ears rather than sequential tones in one ear, suggesting that the illusion involves a misattribution of time across perceptual streams, rather than a misattribution of location within a stream. The results provide new insights into the mechanisms of binaural streaming and synchronous sound segregation.本研究旨在探究与多伊奇（Deutsch）八度错觉（octave illusion）相似的刺激所诱发的模糊知觉背后的神经关联与加工机制。该刺激的呈现范式为：双耳各接收一组高低频率纯音交替的序列，双耳序列完全一致，但相位相反——左耳接收的序列为高-低-高……，右耳则为低-高-低……。受试者通常会报告感知到高低音交替的听觉错觉，且所有低音均单侧化定位，所有高音则定位至对侧。目前针对该错觉的主流解释认为，其本质是音高与知觉位置的错觉性特征结合。本研究采用心理物理学与脑电图（electroencephalogram, EEG）测量技术，对该主流解释以及另一种涉及同步与序列听觉流分离的备选假说进行验证，并探究该错觉的潜在神经关联。研究结果显示，该交替音错觉源于双耳间的同步音对，而非单侧耳内的序列音，这提示该错觉属于知觉流之间的时间归因错误，而非单一知觉流内的位置归因错误。本研究结果为双耳听觉流加工与同步声音分离的机制提供了全新的研究视角。