Effects of temporal cueing on residual visual discrimination in blindsight
Effects of temporal cueing on residual visual discrimination in blindsight
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DOI：
10.1016/s0028-3932(98)00084-0
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发表时间：
1999-04-01
期刊：
影响因子：
2.6
通讯作者：
Weiskrantz, L
中科院分区：
文献类型：
--
作者：
Kentridge, RW;Heywood, CA;Weiskrantz, L
我们测试了失明患者GY在空间双选择强迫选择范式(空间2AFC)中识别目标出现在两个位置中的哪一个的能力。在每一次试验中，受试者被要求做出第二次手动回答，表明他是否知道试验期间发生的事件。在注视位置呈现的A.提示可以表示目标在每次实验的10个S持续时间内出现的0.4个S时间段。采用了93%、43%和22%三个对比度的靶点。我们发现，对于每个对比度，GY在盲区辨别目标位置的能力仍然明显高于机会，无论有没有线索。然而，暗示确实显著改善了他在低对比度目标上的表现。当他在他的备用视野中对接近阈值的对比度目标执行类似的任务时，他的辨别能力是有机会的，除非目标的呈现是被暗示的，尽管他报告说他对这些刺激的意识比他在盲区对低对比度刺激的意识更强。这些结果与之前报道的猴子在婴儿或成年时视觉皮质受损的结果进行了比较。我们得出的结论是：(1)GY的盲视与近阈值的正常视力有质的区别。(2)即使在没有时间线索的情况下，他的盲目行为也与婴幼儿受损的猴子有共同之处。(3)剩余视力受与时间线索相关的注意过程或觉醒过程的调节。(C)1999爱思唯尔科学有限公司。保留所有权利。
We tested the ability of a blindsight patient, GY,to identify in which of two locations a target was presented in a spatial two-alternative forced-choice paradigm (spatial 2AFC). On each trial the subject was asked to make a second manual response indicating whether he had had any awareness of an event occurring during the trial. A. cue, presented at the fixation location, could signal the 0.4 s period over which the target appeared within the 10 s duration of each trial. Targets of three contrasts, 93, 43 and 22% were used. We found that GY's ability to discriminate the location of targets in his blind field remained significantly above chance, with and without cueing, for each contrast. Cueing, did, however, significantly improve his performance for low contrast targets. When he performed a similar task with near threshold contrast targets in his spared visual field his discrimination was at chance unless the presentation of targets was cued, despite his reporting more awareness for these stimuli than he did for low-contrast stimuli in his blind field. These results are compared with those previously reported in monkeys who received lesions to their visual cortices as infants or adults. We conclude that (1) GY's blindsight is qualitatively different from near-threshold normal vision. (2) In common with infant-lesioned monkeys his blindsight remains even in the absence of temporal cues. (3) Residual vision is subject to modulation by attentional processes, or arousal, associated with temporal cueing. (C) 1999 Elsevier Science Ltd. All rights reserved.