Cardenas Valerie A, Chao Linda L, Blumenfeld Rob, Song Enmin, Meyerhoff Dieter J, Weiner Michael W, Studholme Colin
Magnetic Resonance Unit, San Francisco Veterans Administration Medical Center, San Francisco, California 94121, USA.
Hum Brain Mapp. 2005 Jul;25(3):317-27. doi: 10.1002/hbm.20103.
Despite the clinical significance of event-related potential (ERP) latency abnormalities, little attention has focused on the anatomic substrate of latency variability. Volume conduction models do not identify the anatomy responsible for delayed neural transmission between neural sources. To explore the anatomic substrate of ERP latency variability in normal adults using automated measures derived from magnetic resonance imaging (MRI), ERPs were recorded in the visual three-stimulus oddball task in 59 healthy participants. Latencies of the P3a and P3b components were measured at the vertex. Measures of local anatomic size in the brain were estimated from structural MRI, using tissue segmentation and deformation morphometry. A general linear model was fitted relating latency to measures of local anatomic size, covarying for intracranial vault volume. Longer P3b latencies were related to contractions in thalamus extending superiorly into the corpus callosum, white matter (WM) anterior to the central sulcus on the left and right, left temporal WM, the right anterior limb of the internal capsule extending into the lenticular nucleus, and larger cerebrospinal fluid volumes. There was no evidence for a relationship between gray matter (GM) volumes and P3b latency. Longer P3a latencies were related to contractions in left temporal WM, and left parietal GM and WM near the interhemispheric fissure. P3b latency variability is related chiefly to WM, thalamus, and lenticular nucleus, whereas P3a latency variability is not related as strongly to anatomy. These results imply that the WM connectivity between generators influences P3b latency more than the generators themselves do.
尽管事件相关电位（ERP）潜伏期异常具有临床意义，但很少有人关注潜伏期变异性的解剖学基础。容积传导模型无法确定导致神经源之间神经传导延迟的解剖结构。为了使用源自磁共振成像（MRI）的自动测量方法探索正常成年人ERP潜伏期变异性的解剖学基础，我们在59名健康参与者的视觉三刺激Oddball任务中记录了ERP。在头顶测量P3a和P3b成分的潜伏期。利用组织分割和变形形态测量法，从结构MRI估计脑内局部解剖大小的测量值。拟合一个一般线性模型，将潜伏期与局部解剖大小的测量值相关联，并对颅内腔容积进行协变量分析。较长的P3b潜伏期与丘脑收缩有关，丘脑收缩向上延伸至胼胝体、左右中央沟前方的白质（WM）、左侧颞叶WM、延伸至豆状核的右侧内囊前肢，以及较大的脑脊液体积。没有证据表明灰质（GM）体积与P3b潜伏期之间存在关系。较长的P3a潜伏期与左侧颞叶WM、以及半球间裂附近的左侧顶叶GM和WM收缩有关。P3b潜伏期变异性主要与WM、丘脑和豆状核有关，而P3a潜伏期变异性与解剖结构的关系不那么密切。这些结果表明，发生器之间的WM连接性对P3b潜伏期的影响大于发生器本身。
