Express saccades: is bimodality a result of the order of stimulus presentation?
Express saccades: is bimodality a result of the order of stimulus presentation?
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DOI：
10.1016/s0042-6989(01)00007-4
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发表时间：
2001-04-01
期刊：
影响因子：
1.8
通讯作者：
Carpenter, RHS
中科院分区：
文献类型：
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作者：
Carpenter, RHS
受试者执行了一项saccadic间隙任务，其中固定目标在外围刺激出现之前熄灭了一段时间。大多数人还显示了主要，较慢的分布之外的短期快速扫视。但是，近距离分析表明，几乎所有这种双峰性都是由于进行试验的较旧而造成的：快速响应几乎完全来自试验，该试验与前面试验相反。当它在同一侧时较慢。使用新型两间隙任务的进一步实验表明，这种试验效应是由于一个试验调节了下一个试验的第一个扫视。因此，在两间隙的任务中，如果第二个扫视的延迟属于类别，则它的延迟与紧接的前方方向相同：这可能是动眼系统预测目标方向的结果，扫视速度朝着预期的方向朝着较短的延迟。因此，双峰性似乎并不是动眼系统中某种随机化过程的结果：相反，这是通常进行Saccadic实验的结果。 （c）2001 Elsevier Science Ltd.保留所有权利。
Subjects undertook a saccadic gap task, in which the fixation target is extinguished for a period before the appearance of the peripheral stimulus. The majority showed a population of short-latency express saccades in addition to the main, slower, distribution. However, closer analysis showed that nearly all of this bimodality was due to the older in which trials were performed: the faster responses came almost entirely from trials in which the target was on the opposite side from the preceding trial. slower ones when it was on the same side. Further experiments using a novel two-gap task demonstrated that this inter-trial effect is due to the return eye movement of one trial conditioning the first saccade of the next. Consequently, in a two-gap task the latency of the second saccade falls into the faster category if it is in the same direction as the immediately preceding one: this may be the result of the oculomotor system predicting target direction, saccades in the expected direction having a shorter latency. It seems therefore that the bimodality is not primarily the result of some kind of randomising process within the oculomotor system: rather, it is a consequence of the way in which saccadic experiments are normally conducted. (C) 2001 Elsevier Science Ltd. All rights reserved.