2008-1-22 10:12:48

眼见不如耳闻—大脑对声音更敏感

生物谷报道：人的大脑能够觉察环境中影像和声音的细微变化，不管是一闪而过的蚊子还是吉他手一个微小的失误，我们都能够立即轻而易举地觉察到。然而，已有研究发现，大脑中变化前的映像和变化后的映像，即使间隔了一小段时间，也会干扰大脑检测视觉差异的能力。

法国波尔多大学（University of Bordeaux）的科学家Laurent Demany等人说，大脑必定以某种方式记住变化前的情景。许多实验已经证明，哪怕是100毫秒的短暂时间间隔，也会严重干扰我们觉察周围环境复杂图像变化的能力。这种现象被称为“动态性失明”（change blindness）。

上述这些科学家最近研究了时间间隔对大脑觉察声音变化的影响。他们的目的是通过研究确定，大脑是否用相同的机制来觉察影像和声音的变化。参与试验的人要在许多音调中，觉察到一个音调的音高发生的变化。试验时，研究了不同的变化前声音复杂程度和安静的时间间隔。

研究人员本来以为，若是与觉察图像变化的过程相似，大脑将在复杂的声音环境中，能记住的变化比在简单的环境中要少。但是他们的研究结果发现，尽管有时间上的延迟，参与实验者还是能够记住非常复杂的、多达12种音调的变化。

这项研究的结果表明，与影像相比，人类大脑使用更复杂的机制来记住声音，因此某种程度上说，人对声音的变化比对影像的变化更敏感。

该研究结果发表在2008月1月的Psychological Science上。

生物谷推荐原始出处：

Psychological Science

Volume 19 Issue 1 Page 85-91, January 2008

To cite this article: Laurent Demany, Wiebke Trost, Maja Serman, Catherine Semal (2008)
Auditory Change Detection: Simple Sounds Are Not Memorized Better Than Complex Sounds
Psychological Science 19 (1), 85–91.
doi:10.1111/j.1467-9280.2008.02050.x

Auditory Change Detection: Simple Sounds Are Not Memorized Better Than Complex Sounds

Laurent Demany11Université Bordeaux 2 and Centre National de la Recherche Scientifique, Bordeaux, France,
Wiebke Trost11Université Bordeaux 2 and Centre National de la Recherche Scientifique, Bordeaux, France,
Maja Serman11Université Bordeaux 2 and Centre National de la Recherche Scientifique, Bordeaux, France, and
Catherine Semal11Université Bordeaux 2 and Centre National de la Recherche Scientifique, Bordeaux, France

1Université Bordeaux 2 and Centre National de la Recherche Scientifique, Bordeaux, France
ABSTRACT—Previous research has shown that the detectability of a local change in a visual image is essentially independent of the complexity of the image when the interstimulus interval (ISI) is very short, but is limited by a low-capacity memory system when the ISI exceeds 100 ms. In the study reported here, listeners made same/different judgments on pairs of successive "chords" (sums of pure tones with random frequencies). The change to be detected was always a frequency shift in one of the tones, and which tone would change was unpredictable. Performance worsened as the number of tones increased, but this effect was not larger for 2-s ISIs than for 0-ms ISIs. Similar results were obtained when a chord was followed by a single tone that had to be judged as higher or lower than the closest component of the chord. Overall, our data suggest that change detection is based on different mechanisms in audition and vision.