Van Gelder P, Lebedev S, Liu P M, Tsui W H
Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY 10962.
Vision Res. 1995 Mar;35(5):667-78. doi: 10.1016/0042-6989(94)00161-e.
The dramatic improvement in smooth pursuit performance seen while analyzing the pursuit target has been ascribed to attention enhancement. With a periodic constant velocity target trajectory we ran a concurrent listening condition instead, to see if this mild distraction would degrade performance. Performance improved somewhat with the listening task, suggesting that displacing attentional effort from pursuit accuracy, rather than increasing it, brings better pursuit performance. Catch-up saccades were evenly distributed across tracking, listening, and target analysis conditions, but anticipatory and overshooting saccades were almost eliminated with target analysis. Thus the poor pursuit seems to have been caused by anticipatory and overshooting saccades, produced erroneously in the attempt to perform purposive smooth pursuit. Pursuit velocity immediately following anticipatory saccades was reduced such that the target would catch up with the point of gaze when it reached the endpoint of its trajectory, indicating a predictive goal other than instantaneous target foveation and velocity match.
在分析追踪目标时观察到的平滑追踪性能的显著改善归因于注意力增强。我们采用周期性匀速目标轨迹，同时设置了一个听觉任务，以观察这种轻微干扰是否会降低性能。在执行听觉任务时，性能有所提高，这表明将注意力从追踪准确性上转移，而非增加注意力，能带来更好的追踪性能。在追踪、听觉和目标分析条件下，校正性扫视分布均匀，但在目标分析时，预期性扫视和过冲性扫视几乎消失。因此，较差的追踪似乎是由预期性扫视和过冲性扫视导致的，这些扫视是在试图进行有目的的平滑追踪时错误产生的。预期性扫视之后的追踪速度降低，以便当目标到达轨迹终点时，目标能够赶上注视点，这表明存在一个预测性目标，而非瞬时目标中央凹成像和速度匹配。
