Fjell Anders M, Walhovd Kristine B, Fischl Bruce, Reinvang Ivar
Department of Psychology, University of Oslo, Norway.
Hum Brain Mapp. 2007 Nov;28(11):1098-116. doi: 10.1002/hbm.20335.
The purpose of the study was to assess the relationship between the P3a/P3b brain potentials, cortical thickness, and cognitive function in aging. Thirty-five younger and 37 older healthy participants completed a visual three-stimuli oddball ERP (event-related potential)-paradigm, a battery of neuropsychological tests, and MRI scans. Groups with short vs. long latency, and low vs. high amplitude, were compared on a point by point basis across the entire cortical mantle. In the young, thickness was only weakly related to P3. In the elderly, P3a amplitude effects were found in parietal areas, the temporoparietal junction, and parts of the posterior cingulate cortex. P3b latency was especially related to cortical thickness in large frontal regions. Path models with the whole sample pooled together were constructed, demonstrating that cortical thickness in the temporoparietal cortex predicted P3a amplitude, which in turn predicted executive function, and that thickness in orbitofrontal cortex predicted P3b latency, which in turn predicted fluid function. When age was included in the model, the relationship between P3 and cognitive function vanished, while the relationship between regional cortical thickness and P3 remained. It is concluded that thickness in specific cortical areas correlates with scalp recorded P3a/P3b in elderly, and that these relationships differentially mediate higher cognitive function.
这项研究的目的是评估衰老过程中P3a/P3b脑电、皮质厚度与认知功能之间的关系。35名年轻健康参与者和37名年长健康参与者完成了视觉三刺激Oddball事件相关电位（ERP）范式、一系列神经心理学测试以及磁共振成像（MRI）扫描。对潜伏期短与长、波幅低与高的组在整个皮质表面逐点进行比较。在年轻人中，皮质厚度与P3仅存在微弱关联。在老年人中，顶叶区域、颞顶联合区以及部分后扣带回皮质发现了P3a波幅效应。P3b潜伏期与额叶大区域的皮质厚度尤其相关。构建了将整个样本合并在一起的路径模型，结果表明颞顶叶皮质的厚度可预测P3a波幅，进而预测执行功能，眶额皮质的厚度可预测P3b潜伏期，进而预测流体智力功能。当模型纳入年龄因素时，P3与认知功能之间的关系消失，而区域皮质厚度与P3之间的关系依然存在。研究得出结论，特定皮质区域的厚度与老年人头皮记录的P3a/P3b相关，并且这些关系以不同方式介导了更高层次的认知功能。
