Department of Diagnostic Imaging, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada.
Brain Topogr. 2011 Oct;24(3-4):261-70. doi: 10.1007/s10548-011-0192-z. Epub 2011 Jul 19.
Face recognition skills improve steadily across childhood, yet few studies have investigated the development of the neural sources underlying these processes. We investigated the developmental changes in brain activity related specifically to face recognition, using magnetoencephalography (MEG). We studied 70 children (6-19 years) and 20 young adults. Photographs of 240 neutral faces were used in two blocks of 1-back recognition tasks; one block contained faces upright and in the other block, faces were presented inverted. MEG activity was recorded on a 151 sensor CTF/MISL system. A structural MRI was acquired for all subjects. We focussed on the repetition effects of the faces, in a 280-680 ms window, contrasting the repeated faces with the first presentation of the faces. The analyses showed reliable right hippocampal activation across all age groups, and a right inferior frontal activation that emerged for repeated, recognised faces at 10-11 years of age. The hippocampi are implicated in memory function and we demonstrate that the right hippocampus is specifically involved for face recognition. Further, we determined that this comes on-line by early school age, which is consistent with the known early maturation of the hippocampi. In contrast, we show that the right inferior frontal areas do not come on-line until later in childhood, consistent with the protracted development of the frontal cortices. These data support the hypothesis that different age groups use different strategies and neural structures for face recognition.
面部识别能力在儿童期稳步提高，但很少有研究调查这些过程背后的神经来源的发展。我们使用脑磁图（MEG）研究了专门与面部识别相关的大脑活动的发展变化。我们研究了 70 名儿童（6-19 岁）和 20 名年轻人。在两个 1 回认任务的块中使用了 240 张中性面孔的照片；一个块包含直立的面孔，而在另一个块中，面孔呈现倒置。MEG 活动在一个 151 个传感器 CTF/MISL 系统上记录。所有受试者都进行了结构 MRI。我们专注于面孔的重复效应，在 280-680ms 的窗口中，将重复的面孔与面孔的首次呈现进行对比。分析显示，所有年龄组都有可靠的右侧海马激活，并且在 10-11 岁时，识别出的重复面孔会出现右侧下额叶激活。海马体与记忆功能有关，我们证明右侧海马体专门参与面部识别。此外，我们确定这是在早期学校年龄开始的，这与海马体的早期成熟是一致的。相比之下，我们表明右侧额下区域直到儿童后期才开始在线，这与额皮质的发育过程一致。这些数据支持了不同年龄组使用不同策略和神经结构进行面部识别的假设。
