OCULAR VERGENCE UNDER NATURAL CONDITIONS .2. GAZE SHIFTS BETWEEN REAL TARGETS DIFFERING IN DISTANCE AND DIRECTION
OCULAR VERGENCE UNDER NATURAL CONDITIONS .2. GAZE SHIFTS BETWEEN REAL TARGETS DIFFERING IN DISTANCE AND DIRECTION
复制标题
DOI：
10.1098/rspb.1989.0031
复制
发表时间：
1989-05-22
期刊：
影响因子：
--
通讯作者：
COLLEWIJN, H
中科院分区：
文献类型：
--
作者：
ERKELENS, CJ;STEINMAN, RM;COLLEWIJN, H
水平双眼眼球运动的三个科目记录与巩膜传感器线圈旋转磁场技术在自愿转移的目光之间对固定的，真实的，连续可见的目标。靶对位于沿正中面（要求对称聚散度）的沿着方向或正中面的两侧（要求不对称聚散度）。对称性聚散主要是平滑的，但它往往是由小的，分离性扫视的帮助。 峰值聚散速度非常高;它们从约50 °增加。s-1，用于5.0 °的聚散度变化。至150至200度之间。对于34 °的聚散度变化为S-1。趋同和趋异之间的差异是特殊的。不对称聚散度，要求聚散度为11 °。与45 °的版本相结合，主要是扫视。不平等的扫视介导几乎所有（95%）的聚散度所需的发散方向，而75%的聚散度所需的收敛方向是由不平等的扫视介导的，与其余的收敛介导的顺利聚散度，完成后的扫视。这些扫视期间的峰值发散速度非常高（180 °）。s-1，聚散度变化为11 °）;比可比尺寸（14 °）的平滑、对称聚散度变化快得多。峰值会聚扫视速度降低约20%。这种峰值速度的差异是由在所有水平扫视开始时观察到的初始瞬时发散引起的。分离性眼跳的波形与相似大小的共轭眼跳的波形形状不同。分离对中较小的眼跳在时间上被拉长，以便与其较大的同伴眼跳具有相同的持续时间。这些眼跳。这些结果支持了控制扫视和聚散的子系统不是独立的结论。聚散反应是相对缓慢和不完整的单眼观看，排除视差作为一个线索。单眼刺激的聚散度下降的功能，增加老视我们的三个科目。受试者能够在黑暗中对先前看到和记住的目标产生一些聚散。然而，这种反应是缓慢的，不规则的和短暂的。总之，目标之间的聚散度变化，提供了所有的自然线索的距离，是快速和准确的，他们似乎足以提供有效的双目视觉在自然条件下。根据以前的观察，这一结果是无法预料的，所有这些观察都是在深度线索严重减少的情况下进行的。我们还发现，不对称的聚散度主要是扫视，并得出结论，在每只眼睛的大小不等的扫视的产生是一个正常的功能眼的性能，每当目光之间的距离以及方向不同的目标转移。
Horizontal binocular eye movements of three subjects were recorded with the scleral sensor coil-revolving magnetic field technique during voluntary shifts of gaze between pairs of stationary, real, continuously visible targets. The target pairs were located either along the median plane (requiring symmetrical vergence), or on either side of the median plane (requiring asymmetrical vergence). Symmetrical vergence was primarily smooth, but it was often assisted by small, disjunctive saccades. Peak vergence speeds were very high; they increased from about 50.degree. s-1 for vergence changes of 5.degree. to between 150 and 200.degree. s-1 for vergence changes of 34.degree.. Differences between convergence and divergence were idiosyncratic. Asymmetrical vergence, requiring a vergence of 11.degree. combines with the version of 45.degree., was largely saccadic. Unequal saccades mediated virtually all (95%) of the vergence required in the divergent direction, whereas 75% of the vergence required in the convergent direction was mediated by unequal saccades, with the remaining convergence mediated by smooth vergence, following completion of the saccades. Peak divergence speeds during these saccades were very high (180.degree. s-1 for a change of vergence of 11.degree.); much faster than the smooth, symmetrical vergence change of comparable size (14.degree.). Peak convergent saccadic speeds were about 20% lower. This difference in peak speed was caused by an initial, transient divergence, observed at the beginning of all horizontal saccades. The waveform of disjunctive saccades did not have the same shape as the waveform of conjugate saccades of similar size. The smaller saccase of the disjunctive pair was stretched out in time so as to have the same duration as its larger, companion saccade. These saccade. These results permitted the conclusion that the subsystems controlling saccades and vergence are not independent. Vergence responses were relatively slow and incomplete with monocular viewing, which excluded disparity as a cue. Monocularly stimulated vergence decreased as a function of the increasing presbyopia of our three subjects. Subjects were able to generate some vergence in darkness towards previously seen and remembered targets. Such responses, however, were slow, irregular and evanescent. In conclusion, vergence shifts between targets, which provided all natural cues to distance, were fast and accurate; they appeared adequate to provide effective binocular vision under natural conditions. This result could not have been expected on the basis of previous observations, all of which had been made with severely reduced cues to depth. We also found that asymmetric vergence was largely saccadic and conclude that the generation of saccades of unequal sizes in each of the eyes is a normal feature of oculomotor performance whenever gaze is shifted between targets that differ in distance as well as direction.