Hearing Is Believing: Sounds Alter Our Visual Perception耳听为实：声音改变我们的视觉感知

Perception generally feels effortless. If you hear a bird chirping1 and look out the window， it hardly feels like your brain has done anything at all when you recognize that chirping critter2 on your windowsill as a bird.

一般来说，感知似乎无需费力。当你随着一声鸟语啁啾向窗外看去，你会认出窗沿那唧唧喳喳的小动物是一只鸟。整个过程几乎感觉不到大脑做了什么。

In fact， research in Psychological Science suggests that these kinds of audio cues can not only help us to recognize objects more quickly but can even alter our visual perception. That is， pair birdsong with a bird and we see a bird—but replace that birdsong with a squirrel’s chatter3， and we’re not quite so sure what we’re looking at.

一项刊于《心理科学》的研究表明，这类声音信号不光能让人们更快地辨别出物体，甚至还能改变人们的视觉感知。也就是说，把鸟鸣与鸟相匹配，我们才会看到鸟——但若将鸟鸣换成松鼠吱吱的叫声，我们就会拿不准自己所见的到底是什么。

“Your brain spends a significant amount of energy to process the sensory information in the world and to give you that feeling of a full and seamless perception，” said lead author Jamal R. Williams （University of California， San Diego） in an interview. “One way that it does this is by making inferences about what sorts of information should be expected.”

来自加利福尼亚大学圣地亚哥分校的贾迈勒·R.威廉斯是该篇论文的主要作者。“大脑耗费大量精力来处理世上的感官信息，让人们获得完整而连贯的知觉体验。”他在一次采访中提到：“其中一种处理方式就是推测应该期待何种信息。”

Although these “informed guesses” can help us to process information more quickly， they can also lead us astray when what we’re hearing doesn’t match up with what we expect to see， said Williams， who conducted this research with Yuri A. Markov， Natalia A. Tiurina （École Polytechnique Fédérale de Lausanne）， and Viola S. Störmer （University of California， San Diego and Dartmouth College）.

威廉斯说，虽然这种“有根据的猜想”能够帮我们加快信息处理，但如果听到的声音与期待的画面有出入，也可能对我们进行误导。他与尤里·A.马尔科夫、纳塔利娅·A.秋里娜（洛桑联邦理工学院）和维奥拉·S.斯托默（加利福尼亚大学圣地亚哥分校及达特茅斯学院）共同完成了这项研究。

“Even when people are confident in their perception， sounds reliably altered them away from the true visual features that were shown，” Williams said.

“就算人们对自己的知觉怀抱信心，声音依旧会使我们妥妥地偏离真实呈现的视觉特征。”威廉斯说道。

In their first experiment， Williams and colleagues presented 40 participants with figures that depicted two objects at various stages of morphing4 into one another， such as a bird turning into a plane. During this visual discrimination phase， the researchers also played one of two types of sounds： a related sound （in the bird/plane example， a birdsong or the buzz of a plane） or an unrelated sound like that of a hammer hitting a nail.

在第一项实验中，威廉斯和同事们向40名受试者展示了一系列图像，描绘了两个物体相互转化变形的不同阶段，比如一只鸟变成一架飞机。在这一视觉辨别阶段，研究人员还播放了两种声音中的一种：有关联的声音（在鸟和飞机的例子里，是鸟鸣或飞机嗡嗡作响的声音），或者无关联的声音，如锤子敲钉的声音。

Participants were then asked to recall which stage of the object morph they had been shown. To show what they recalled， they used a sliding scale that， in the above example， made the object appear more bird or more plane-like. Participants were found to make their object-morph selection more quickly when they heard related （versus unrelated） sounds and to shift their object-morph selection to more closely match the related sounds that they heard.

之后，受试者需要回忆自己所看到的物体正处于变形的哪一阶段。为了呈现回忆结果，在上例中，他们在滑动量表上选择物体更像鸟还是更像飞机。研究发现，与无关联的声音相比，当听到关联声音时，受试者能够更快选定变形物体，且往往选择与听到的关联声音一致的那种。

“When sounds are related to pertinent5 visual features， those visual features are prioritized and processed more quickly compared to when sounds are unrelated to the visual features. So， if you heard the sound of a birdsong， anything bird-like is given prioritized access to visual perception，” Williams explained. “We found that this prioritization is not purely facilitatory and that your perception of the visual object is actually more bird-like than if you had heard the sound of an airplane flying overhead.”

“与无关联声音相比，如果声音与视觉特征相关，这些特征就会被优先考虑并且得到更快的处理。因此，如果听到鸟鸣声，任何与鸟类相似的物体都会优先进入你的视觉感知。”威廉斯解释道，“我们发现，这种优先并非纯粹的易化作用，而且，听到鸟鸣声与听到飞机飞过的嗡嗡声相比，实际上让人对视觉对象的感知更倾向于鸟。”

In their second experiment， Williams and colleagues explored whether this effect was specific to the visual-discrimination phase of perceptual processing or， alternatively， if sounds might instead shape visual perception by influencing our decision-making processes. To do so， the researchers presented 105 participants with the same task， but this time they played the sounds either while the object morph was on screen or while participants were making their object-morph selection after the original image had disappeared.

在第二项实验中，威廉斯与同事们探究了这种效应在整个知觉处理过程中，是否单单存在于视觉辨别阶段，还是说，声音或许是借由影响决策过程来塑造视觉感知的。为此，研究人员向105名受试者发布了与之前相同的任务，但这次他们放出声音时，要么屏幕上还在显示变形物体，要么受试者在原始图像消失后正完成选择任务。

As in the first experiment， audio input was found to influence participants’ speed and accuracy when the sounds were played while they were viewing the object morph， but it had no effect when the sounds were played while they reported which object morph they had seen.

与第一项实验一样，研究发现，在受试者观看物体变形时播放声音，音频输入会影响受试者决策的速度和准确性。但在受试者报告自己眼中的物体形状时，播放声音则没有影响。

Finally， in a third experiment with 40 participants， Williams and colleagues played the sounds before the object morphs were shown. The goal here was to test whether audio input may influence visual perception by priming6 people to pay more attention to certain objects. This was also found to have no effect on participants’ object-morph selections.

最后，威廉斯和同事们对40名受试者进行了第三项实验。他们在展示物体变形图像之前播放了声音。这项实验的目的是测试音频输入是否会使人们预先关注某些物体，从而影响视觉感知。结果发现，这对受试者的物体变形选择也没有影响。

Taken together， these findings suggest that sounds alter visual perception only when audio and visual input occur at the same time， the researchers concluded.

综上所述，研究人员得出结论：只有当听觉和视觉输入同时出现时，声音才会改变视觉感知。

“This process of recognizing objects in the world feels effortless and fast， but in reality it’s a very computationally intensive process，” Williams said. “To alleviate some of this burden， your brain is going to evaluate information from other senses.”

“辨别世上的物体看似毫不费力，速度也很快，但实际上，这个过程需要大量的计算。”威廉斯说，“为了减轻一些负担，你的大脑会对其他感官提供的信息进行评估。”

（译者单位：湖北三峡职业技术学院）

1 chirping鸟叫；虫鸣。  2 critter生物；动物。  3 chatter唧唧叫；吱吱叫。

4 morph图像变形。

5 pertinent相关的；相宜的。

6 prime事先指点；使（某人）做好准备。