Attention mechanisms for multi-location first- and second-order motion perception
Attention mechanisms for multi-location first- and second-order motion perception
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DOI：
10.1016/s0042-6989(99)00172-8
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发表时间：
2000-01-01
期刊：
影响因子：
1.8
通讯作者：
Dosher, BA
中科院分区：
文献类型：
--
作者：
Lu, ZL;Liu, CQ;Dosher, BA
本研究采用外部噪声加注意的实验范式，研究了在两个空间位置上同时进行的一阶和二阶运动知觉的注意机制。提示参加的位置之一，观察者被指示独立判断的运动方向的一阶（实验1）或二阶（实验2）的运动刺激在这两个位置在每一个审判。在整个试验中，系统控制的外部噪音量被添加到运动显示器中。我们测量运动阈值在三个性能标准在每一个注意x外部噪声条件。我们发现，观察者可以，没有任何损失，同时计算一阶运动方向在两个相距甚远的空间位置在广泛的外部噪声条件。然而，相当大的损失发生在无人值守的位置在处理二阶运动方向在两个分开的空间位置。结果表明：（1）在一阶运动知觉中，视觉系统可以同时在两个相距较远的位置处理运动方向，而不受容量限制;（2）在二阶运动知觉中，视觉系统可以同时在两个相距较远的位置处理运动方向。关注空间位置将该位置处的刺激对比度增强约1.37倍（或等效地，将内部加性噪声减小约0.73倍）。(C)2000爱思唯尔科技有限公司版权所有。
We applied the external noise plus attention paradigm to study attention mechanisms involved in concurrent first-order and second-order motion perception at two spatial locations. Cued to attend to one of the locations, the observer was instructed to independently judge direction of motion of either first-order (Experiment 1) or second-order (Experiment 2) motion stimuli at both locations in every trial. Across trials, systematically controlled amounts of external noise were added to the motion displays. We measured motion threshold at three performance criteria in every attention x external noise condition. We find that observers could, without any loss, simultaneously compute first-order motion direction at two widely separated spatial locations across a broad range of external noise conditions. However, considerable loss occurred at the unattended location in processing second-order motion direction at two separated spatial locations. We conclude that, under the conditions investigated in the current study, (1) in first-order motion perception, the visual system could simultaneously process motion direction at two widely separated locations without any capacity limitation; (2) in second-order motion perception. attending to a spatial location enhances stimulus contrast at that location by a factor of about 1.37 (or equivalently, reduces the internal additive noise by a factor of about 0.73). (C) 2000 Elsevier Science Ltd. All rights reserved.