Norena A, Micheyl C, Chery-Croze S
CNRS UMR 5020, Laboratoire 'Neurosciences and Systèmes Sensoriels', Hôpital Edouard Herriot, Pavillon U, Place d'Arsonval, 69437 Cedex 03, Lyon, France.
Hear Res. 2000 Nov;149(1-2):24-32. doi: 10.1016/s0378-5955(00)00158-1.
The Zwicker tone (ZT) is an auditory after-image, i.e. a tonal sensation that occurs following the presentation of notched noise. In the present study, the hypothesis that neural lateral inhibition is involved in the generation of this auditory illusion was investigated in humans through differences in perceptual detection thresholds measured following broadband noise, notched noise, and low-pass noise stimulation. The detection thresholds were measured using probe tones at several frequencies, within as well as outside the suppressed frequency range of the notched noise, and below as well as above the corner frequency of the low-pass noise. Thresholds measured after broadband noise using a sequence of four 130-ms probe tones (with a 130-ms inter-burst interval) proved to be significantly smaller that those measured using the same probe tones after notched noise at frequencies falling within the notch, but larger for frequencies on the outer edges of the noise. Thresholds measured following low-pass noise using the same sequence of probe tones were found to be smaller at frequencies slightly above the corner, but larger at lower, neighboring frequencies. This pattern of results is consistent with the hypothesis that the changes in auditory sensitivity induced by stimuli containing sharp spectral contrasts reflect lateral inhibition processes in the auditory system. The potential implications of these findings for the understanding of the mechanisms underlying the generation of auditory illusions like the ZT or tinnitus are discussed.
齐克纳音调（ZT）是一种听觉后像，即一种在呈现带凹口噪声后出现的音调感觉。在本研究中，通过比较在宽带噪声、带凹口噪声和低通噪声刺激后测量的感知检测阈值的差异，在人类中研究了神经侧向抑制参与这种听觉错觉产生的假设。使用多个频率的探测音测量检测阈值，这些频率在带凹口噪声的抑制频率范围内外，以及在低通噪声的截止频率上下。使用四个130毫秒探测音序列（突发间隔为130毫秒）在宽带噪声后测量的阈值，被证明显著小于在带凹口噪声频率落在凹口内时使用相同探测音测量的阈值，但对于噪声外边缘的频率则更大。使用相同探测音序列在低通噪声后测量的阈值，发现在略高于截止频率的频率处较小，但在较低的相邻频率处较大。这种结果模式与以下假设一致，即包含尖锐频谱对比度的刺激引起的听觉敏感性变化反映了听觉系统中的侧向抑制过程。讨论了这些发现对理解像ZT或耳鸣这样的听觉错觉产生机制的潜在影响。
