Dombrowe Isabel
Department of Cognitive Psychology: Judgment, Decision Making, Action, FernUniversität, Hagen, Germany.
Department of Experimental Psychology, Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany.
PeerJ. 2018 Mar 14;6:e4493. doi: 10.7717/peerj.4493. eCollection 2018.
The eye movement system reacts very systematically to visual transients that are presented during the planning phase of a saccade. About 50 to 70 ms after the onset of a transient, the number of saccades that are started decreases, a phenomenon that has been termed saccadic inhibition. Saccades started just before this time window are hypometric compared to regular saccades, presumably because the presentation of the transient stops them in mid-flight. Recent research investigating the properties of repeated saccades to fixed locations found that these early saccades were additionally faster than expected from the main sequence relation, suggesting that a saccadic dead time during which saccades can no longer be modified does not exist. The present study investigated the properties of saccades to random locations in a guided saccade task. As expected, early saccades starting just before the saccadic inhibition dip in frequency were hypometric. Their velocity profiles implied that these saccades were actively stopped after reaching peak velocity. However, the peak velocities of these saccades did not generally deviate from the main sequence relation. The question whether an active stop of early saccades is incompatible with the idea of a saccadic dead time is open to debate.
眼动系统对扫视计划阶段呈现的视觉瞬变反应非常有规律。在瞬变开始后约50至70毫秒，开始的扫视次数减少，这一现象被称为扫视抑制。在此时间窗口之前开始的扫视与正常扫视相比幅度变小，大概是因为瞬变的呈现使其在中途停止。最近关于对固定位置重复扫视特性的研究发现，这些早期扫视比主序列关系预期的还要快，这表明不存在扫视无法再被修改的扫视停滞期。本研究在引导扫视任务中研究了向随机位置扫视的特性。正如预期的那样，恰好在扫视抑制频率下降之前开始的早期扫视幅度变小。它们的速度曲线表明这些扫视在达到峰值速度后被主动停止。然而，这些扫视的峰值速度通常并未偏离主序列关系。早期扫视的主动停止是否与扫视停滞期的概念不相容这一问题仍有待讨论。
