Courchesne E, Ganz L, Norcia A M
Child Dev. 1981 Sep;52(3):804-11.
Event-related brain potentials (ERPs) in response to tachistoscopically presented photographs of 2 human faces were recorded for 4--7-month-old infants. For each infant 1 face was chosen to be presented frequently (p = .88, a low-information event) and the other infrequently (p = .12, a high-information event). Both types of events elicited in our infants a long-latency negative ERP wave (ca. 700 msec), termed Nc, and a long-latency positive wave (ca. 1,360 msec), termed Pc. We found that the discrepant, infrequently presented face elicited Nc waves which were higher in amplitude and longer in latency than those elicited by the frequent face. These differences suggest that our infants were able to remember the frequently presented face from trial to trial and to discriminate it from the discrepant face. The discrepant event elicited Pc waves which were insignificantly higher in amplitude than those elicited by frequent events. In adults and children, discrepant events have been found by numerous researchers to elicit positive P3 waves (latency ca. 300--800 msec). In our study, however, such waves could not be discerned. So, of all of the ERP waves which have been related to cognitive processes, the wave which is maturationally the earliest to appear is the Nc wave, which has been related to the perception of attention-getting events or events of interest to the subject. Our findings suggest that ERP responses could provide a sensitive means for investigating infant cognitive development since they do not depend upon an integrated motor-response system.
我们记录了4至7个月大婴儿对通过速示器呈现的两张人脸照片的事件相关脑电位（ERP）。对于每个婴儿，选择一张脸频繁呈现（概率p = 0.88，低信息事件），另一张脸不频繁呈现（概率p = 0.12，高信息事件）。这两种类型的事件在我们的婴儿中均引发了一个长潜伏期负向ERP波（约700毫秒），称为Nc波，以及一个长潜伏期正向波（约1360毫秒），称为Pc波。我们发现，差异较大、不频繁呈现的脸所引发的Nc波，其振幅更高，潜伏期更长，高于频繁呈现的脸所引发的Nc波。这些差异表明，我们的婴儿能够在每次试验中记住频繁呈现的脸，并将其与差异较大的脸区分开来。差异事件引发的Pc波，其振幅仅略高于频繁事件引发的Pc波。众多研究人员发现，在成人和儿童中，差异事件会引发正向P3波（潜伏期约300 - 800毫秒）。然而，在我们的研究中，未能辨别出此类波。所以，在所有与认知过程相关的ERP波中，成熟上最早出现的波是Nc波，它与吸引注意力的事件或受试者感兴趣的事件的感知有关。我们的研究结果表明，ERP反应可以为研究婴儿认知发展提供一种敏感的方法，因为它们不依赖于完整的运动反应系统。
