Department of Psychology, The Hebrew University of Jerusalem, Jerusalem, Israel.
Neurology. 2010 Dec 7;75(23):2110-6. doi: 10.1212/WNL.0b013e318201526e.
Understanding the maturation and organization of cognitive function in the brain is a central objective of both child neurology and developmental cognitive neuroscience. This study focuses on episodic memory encoding of verbal information by children, a cognitive domain not previously studied using fMRI.
Children from 7 to 19 years of age were scanned at 1.5-T field strength using event-related fMRI while performing a novel verbal memory encoding paradigm in which words were incidentally encoded. A subsequent memory analysis was performed. SPM2 was utilized for whole brain and region-of-interest analyses of data. Both whole-sample intragroup analyses and intergroup analyses of the sample divided into 2 subgroups by age were conducted.
Importantly, behavioral memory performance was equal across the age range of children studied. Encoding-related activation in the left hippocampus and bilateral basal ganglia declined as age increased. In addition, while robust blood oxygen level-dependent signal was found in left prefrontal cortex with task performance, no encoding-related age-modulated prefrontal activation was observed in either hemisphere.
These data are consistent with a developmental pattern of verbal memory encoding function in which left hippocampal and bilateral basal ganglionic activations are more robust earlier in childhood but then decline with age. No encoding-related activation was found in prefrontal cortex which may relate to this region's recognized delay in biologic maturation in humans. These data represent the first fMRI demonstration of verbal encoding function in children and are relevant developmentally and clinically.
理解大脑中认知功能的成熟和组织是儿童神经病学和发展认知神经科学的核心目标。本研究关注儿童的言语信息情节记忆编码，这是一个以前没有使用 fMRI 研究过的认知领域。
7 至 19 岁的儿童在 1.5-T 场强下使用事件相关 fMRI 进行扫描，同时执行一种新的言语记忆编码范式，在这种范式中，单词是偶然编码的。随后进行了后续记忆分析。SPM2 用于对数据进行全脑和感兴趣区域分析。对整个样本进行了组内分析，对按年龄分为 2 个亚组的样本进行了组间分析。
重要的是，研究中儿童的行为记忆表现是一致的。随着年龄的增长，左海马体和双侧基底节的编码相关激活减少。此外，虽然在左前额叶皮层中发现了与任务表现相关的强烈血氧水平依赖信号，但在两个半球中都没有观察到与年龄相关的前额叶编码激活。
这些数据与言语记忆编码功能的发展模式一致，即左海马体和双侧基底节的激活在儿童早期更为强烈，但随着年龄的增长而下降。在与年龄相关的前额叶皮层中没有发现与编码相关的激活，这可能与该区域在人类中生物成熟的延迟有关。这些数据代表了儿童言语编码功能的首次 fMRI 证明，具有发展和临床相关性。
