Alvarez Tara L, Alkan Yelda, Gohel Suril, Douglas Ward B, Biswal Bharat B
Department of Biomedical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102, USA.
Vision Res. 2010 Oct 12;50(21):2163-75. doi: 10.1016/j.visres.2010.08.018. Epub 2010 Aug 20.
The purpose of this study is to investigate the functional neural anatomy that generates vergence eye movement responses from predictive versus random symmetrical vergence step stimuli in humans and compare it to a similar saccadic task via the blood oxygenation level dependent signal from functional MRI.
Eight healthy subjects participated in fMRI scans obtained from a 3T Siemens Allegra scanner. Subjects tracked random and predictable vergent steps and then tracked random and predictable saccadic steps each within a block design. A general linear model (GLM) was used to determine significantly (p < 0.001) active regions of interest through a combination of correlation threshold and cluster extent. A paired t-test of the GLM beta weight coefficients was computed to determine significant spatial differences between the saccade and vergence data sets.
Predictive saccadic and vergent eye movements induced many common sites of significant functional cortical activity including: the dorsolateral prefrontal cortex (DLPFC), parietal eye field (PEF), cuneus, precuneus, anterior and posterior cingulate, and the cerebellum. However, differentiation in spatial location was observed within the frontal lobe for the functional activity of the saccadic and vergent network induced while studying prediction. A paired t-test of the beta weights from the individual subjects showed that peak activity induced by predictive versus random vergent eye movements was significantly (t > 2.7, p < 0.03) more anterior within the frontal eye field (FEF) and the supplementary eye field (SEF) when compared to the functional activity from predictive saccadic eye movements.
This research furthers our knowledge of which cortical sites facilitate a subject's ability to predict within the vergence and saccade networks. Using a predictive versus random visual task, saccadic and vergent eye movements induced activation in many shared cortical sites and also stimulated differentiation in the FEF and SEF.
本研究旨在探究人类在预测性与随机对称的聚散性阶跃刺激下产生聚散性眼球运动反应的功能性神经解剖结构，并通过功能磁共振成像的血氧水平依赖信号，将其与类似的扫视任务进行比较。
8名健康受试者参与了由3T西门子Allegra扫描仪进行的功能磁共振成像扫描。受试者在组块设计中分别追踪随机和可预测的聚散性阶跃以及随机和可预测的扫视性阶跃。通过结合相关阈值和聚类范围，使用一般线性模型（GLM）来确定显著（p < 0.001）活跃的感兴趣区域。计算GLMβ权重系数的配对t检验，以确定扫视和聚散数据集之间的显著空间差异。
预测性扫视和聚散性眼球运动诱发了许多共同的显著功能性皮质活动部位，包括：背外侧前额叶皮质（DLPFC）、顶叶眼区（PEF）、楔叶、楔前叶、前扣带回和后扣带回以及小脑。然而，在研究预测时，扫视和聚散网络诱发功能活动在额叶内观察到空间位置的差异。对个体受试者β权重的配对t检验表明，与预测性扫视性眼球运动的功能活动相比，预测性与随机聚散性眼球运动诱发的峰值活动在额叶眼区（FEF）和辅助眼区（SEF）内显著（t > 2.7，p < 0.03）更靠前。
本研究进一步加深了我们对哪些皮质部位有助于受试者在聚散和扫视网络中进行预测能力的认识。使用预测性与随机视觉任务，扫视和聚散性眼球运动在许多共同的皮质部位诱发激活，同时也刺激了FEF和SEF的分化。
