Neuroscience Unit, Institute of Biomedicine/Physiology, University of Helsinki, Helsinki, Finland.
Brain Cogn. 2013 Mar;81(2):203-14. doi: 10.1016/j.bandc.2012.11.003. Epub 2012 Dec 20.
Developmental studies have demonstrated that cognitive processes such as attention, suppression of interference and memory develop throughout childhood and adolescence. However, little is currently known about the development of top-down control mechanisms and their influence on cognitive performance. In the present study, we used functional magnetic resonance imaging to investigate modulation of activity in the ventral visual cortex in healthy 7-11-year-old children and young adults. The participants performed tasks that required attention to either face (Fs task) or scene (Sf task) images while trying to ignore distracting scene or face images, respectively. A face-selective area in the fusiform gyrus (fusiform face area, FFA) and an area responding preferentially to scene images in the parahippocampal gyrus (parahippocampal place area, PPA) were defined using functional localizers. Children responded slower and less accurately in the tasks than adults. In children, the right FFA was less selective to face images and regulation of activity between the Fs and Sf tasks was weaker compared to adults. In the PPA, selectivity to scenes and regulation of activity, there according to the task demands were comparable between children and adults. During the tasks, children activated prefrontal cortical areas including the middle (MFG) and superior (SFG) frontal gyrus more than adults. Functional connectivity between the right FFA and left MFG was stronger in adults than children in the Fs task. Children, on the other hand, had stronger functional connectivity than adults in the Sf task between the right FFA and right PPA and between right MFG and medial SFG. There were no group differences in the functional connectivity between the PPA and the prefrontal cortex (PFC). Together the results suggest that, in 7-11-year-old children, the FFA is still immature, whereas the selectivity to scenes and regulation of activity in the PPA is comparable to adults. The results also indicated functional immaturity of the PFC in children compared to adults and weaker connectivity between the PFC and the rFFA, explaining the weaker regulation of activity in the rFFA between the Fs and Sf tasks.
发展研究表明，注意力、抑制干扰和记忆等认知过程在儿童和青少年时期逐渐发展。然而，目前对于自上而下控制机制的发展及其对认知表现的影响知之甚少。在本研究中，我们使用功能磁共振成像技术研究了健康 7-11 岁儿童和年轻成年人腹侧视觉皮层活动的调制。参与者执行了需要注意面部（Fs 任务）或场景（Sf 任务）图像的任务，同时分别试图忽略分散注意力的场景或面部图像。使用功能定位器定义了梭状回中的一个面部选择性区域（梭状回面部区，FFA）和一个在海马旁回中对场景图像反应优先的区域（海马旁位置区，PPA）。与成年人相比，儿童在任务中的反应速度较慢，准确性较低。在儿童中，右侧 FFA 对面部图像的选择性较低，与 Fs 和 Sf 任务之间的活动调节也较弱。在 PPA 中，根据任务需求，对场景的选择性和活动调节与儿童和成年人相当。在任务期间，儿童比成年人更多地激活额前皮质区域，包括中额（MFG）和上额（SFG）额回。在 Fs 任务中，成人右 FFA 与左 MFG 之间的功能连接强于儿童。另一方面，在 Sf 任务中，儿童右 FFA 与右 PPA 之间以及右 MFG 与内侧 SFG 之间的功能连接强于成人。PPA 与前额叶皮层（PFC）之间的功能连接在组间没有差异。总的来说，研究结果表明，在 7-11 岁的儿童中，FFA 仍然不成熟，而 PPA 对场景的选择性和活动调节与成年人相当。研究结果还表明，与成年人相比，儿童的 PFC 功能不成熟，并且 PFC 与 rFFA 之间的连接较弱，这解释了 rFFA 中 Fs 和 Sf 任务之间活动调节较弱的原因。
