Rapid categorization of natural face images in the infant right hemisphere.
Rapid categorization of natural face images in the infant right hemisphere.
复制标题
DOI：
10.7554/elife.06564
复制
发表时间：
2015-06-02
期刊：
影响因子：
7.7
通讯作者：
Rossion B
中科院分区：
文献类型：
--
作者：
de Heering A;Rossion B
人类在对自然视觉图像进行分类方面的表现超过了自动算法，但这一功能是如何以及何时产生和发展的仍然没有答案。我们记录了4-6个月婴儿的头皮脑电活动，这些婴儿在自然背景中以6张/秒(6赫兹)的速度观看物体的图像。每5个刺激出现一个变化很大的面部图像，在右半球产生精确的1.2赫兹(6赫兹/5)的电生理反应。这种面部选择性响应对于相位置乱的图像是不存在的，因此不是由于低级别信息。这些发现表明，右侧化的面孔选择过程在婴儿大脑中阅读习得之前就已经出现，它可以执行图形-背景分离，并通过大小、视点、光照以及表情、年龄和性别的变化来概括面孔选择反应。这些观察以高度敏感和客观的方法为阐明人脑中自然图像分类的发展过程开辟了一条途径。DOI：http://dx.doi.org/10.7554/eLife.06564.001将人名与面孔对应起来有时可能很有挑战性，但人类通常非常擅长识别面孔。另一方面，计算机经常发现很难将一张脸归类为一张脸。事实上，人脸识别的一个主要挑战出现了，因为人脸有许多不同的形状和大小。此外，照明条件和头部朝向都可能发生变化，这使得挑战变得更加困难。幼儿也表现出对人脸照片的偏好，而不是毫无意义的图像，这表明识别人脸的能力至少部分是与生俱来的。神经成像研究表明，人脸识别依赖于大脑右半球特定区域的活动，而这些区域受损的成年人会失去人脸识别技能。De Heering和Rossion现在已经提供了第一个证据，表明右脑专门用于区分4到6个月大的婴儿的面部自然图像和“非面部物体”。通过使用头皮电极记录婴儿在屏幕上观看图像时大脑中的电活动，德海林和罗松表明，人脸照片引发了右半球明显的电活动模式：这种模式明显不同于动物或物体照片引发的模式。不同性别、不同表情的面孔，以及不同视角、不同光照条件下呈现的面孔，都会引发一致的反应。在一项对照实验中，德海林和罗森证明，低水平的视觉特征，如亮度或对比度的差异，并不有助于对面部的这种选择性反应。这些结果反对这样一种观点，即只有当儿童学习阅读时(即当语言处理开始占据左脑的一部分时)，面孔感知才会分配到大脑的右半球。通过在短时间内(仅5分钟或更短)产生显著的反应，德·海林和罗森开发的方案有可能被证明对研究儿童时期视觉图像知觉的发展变化的研究人员非常有用。DOI：http://dx.doi.org/10.7554/eLife.06564.002
Human performance at categorizing natural visual images surpasses automatic algorithms, but how and when this function arises and develops remain unanswered. We recorded scalp electrical brain activity in 4–6 months infants viewing images of objects in their natural background at a rapid rate of 6 images/second (6 Hz). Widely variable face images appearing every 5 stimuli generate an electrophysiological response over the right hemisphere exactly at 1.2 Hz (6 Hz/5). This face-selective response is absent for phase-scrambled images and therefore not due to low-level information. These findings indicate that right lateralized face-selective processes emerge well before reading acquisition in the infant brain, which can perform figure-ground segregation and generalize face-selective responses across changes in size, viewpoint, illumination as well as expression, age and gender. These observations made with a highly sensitive and objective approach open an avenue for clarifying the developmental course of natural image categorization in the human brain. DOI: http://dx.doi.org/10.7554/eLife.06564.001 Putting names to faces can sometimes be challenging, but humans are generally extremely good at recognising faces. Computers, on the other hand, often find it difficult to categorize a face as a face. Indeed, a major challenge in face recognition arises because faces come in many different shapes and sizes. Moreover, both the lighting conditions and the orientation of the head can change, which makes the challenge even more difficult. Young infants also show a preference for pictures of human faces over nonsense images, which suggests that the ability to recognise faces is at least partly hard-wired. Neuroimaging studies have revealed that face recognition depends on activity in specific regions of the right hemisphere of the brain, and adults who sustain damage to these regions lose their face recognition skills. De Heering and Rossion have now provided the first evidence that the right hemisphere is specialized for distinguishing between natural images of faces and ‘non-face objects’ in infants as young as 4 to 6 months. By using scalp electrodes to record electrical activity in the brain as the infants viewed images on a screen, De Heering and Rossion showed that photographs of human faces triggered a distinct pattern of electrical activity in the right hemisphere: this pattern was clearly different to the patterns triggered by photographs of animals or objects. A consistent response was triggered by faces of different genders and expressions, and by faces presented from various viewpoints and under different lighting conditions. In a control experiment, De Heering and Rossion demonstrated that low-level visual features such as differences in luminance or contrast do not contribute to this selective response to faces. These results argue against the idea that face perception only becomes assigned to the right hemisphere of the brain when children learn to read (that is, when language processing begins to occupy parts of the left hemisphere). By generating significant responses in a short period of time (just five minutes or less), the protocol developed by De Heering and Rossion has the potential to prove very useful to researchers investigating developmental changes to the perception of visual images during childhood. DOI: http://dx.doi.org/10.7554/eLife.06564.002