Vernet Marine, Yang Qing, Daunys Gintautas, Orssaud Christophe, Eggert Thomas, Kapoula Zoï
IRIS Group, CNRS-Collège de France, 11 place Marcelin Berthelot, Paris, France.
Invest Ophthalmol Vis Sci. 2008 Jan;49(1):230-7. doi: 10.1167/iovs.07-0854.
Human ocular saccades are not perfectly yoked; the origin of this disconjugacy (muscular versus central) remains controversial. The purpose of this study was to test a cortical influence on the binocular coordination of saccades.
The authors used a gap paradigm to elicit vertical or horizontal saccades of 10 degrees , randomly interleaved; transcranial magnetic stimulation (TMS) was applied on the posterior parietal cortex (PPC) 100 ms after the target onset.
TMS of the left or right PPC increased (i) the misalignment of the eyes during the presaccadic fixation period; (ii) the size difference between the saccades of the eyes, called disconjugacy; the increase of disconjugacy was significant for rightward and downward saccades after TMS of the right PPC and for downward saccades after TMS of the left PPC.
The authors conclude that the PPC is actively involved in maintaining eye alignment during fixation and in the control of binocular coordination of saccades.
人类眼球扫视并非完全共轭；这种非共轭性的起源（肌肉性还是中枢性）仍存在争议。本研究的目的是测试皮质对扫视双眼协调性的影响。
作者采用间隙范式诱发10度的垂直或水平扫视，随机交错进行；在目标出现后100毫秒对后顶叶皮质（PPC）施加经颅磁刺激（TMS）。
对左侧或右侧PPC进行TMS，增加了（i）扫视前注视期双眼的不对准；（ii）双眼扫视大小的差异，即非共轭性；在右侧PPC进行TMS后，向右和向下扫视的非共轭性增加显著，在左侧PPC进行TMS后，向下扫视的非共轭性增加显著。
作者得出结论，PPC在注视期间积极参与维持眼球对准以及扫视双眼协调性的控制。
