Bidirectional aftereffects in perceived contrast
Bidirectional aftereffects in perceived contrast
复制标题
感知对比度的双向后效
DOI：
10.1167/18.9.12
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发表时间：
2018
影响因子：
1.8
通讯作者：
Isamu Motoyoshi
中科院分区：
文献类型：
--
作者：
Wakana Hata;Isamu Motoyoshi
众所周知，长时间观察高对比度刺激会改变对后续测试刺激的感知。以前的研究认为对比度的变化只报告了感知对比度降低。在这里，我们使用了连续演示的测试和参考刺激，发现感知对比度降低，如果测试有一个较低的对比度比适配器，但显着增强时，测试有一个较高的对比度比适配器。这种双向对比后效没有观察到单一的适配器闪光，但变得越来越明显的重复适配器介绍，从而表明后效是适应的后果，而不是注意力提示或时间排斥。此外，随着我们逐渐抖动适配器的空间位置，感知到的对比度降低减弱，但对于抖动适配器位置的大空间范围，观察到感知到的对比度增强。我们的结论是，后效涉及适应不同的机制与狭窄和广泛的空间调谐。结果表明，视觉系统不仅具有低级别的对比度编码单元，单调增加他们的反应，作为物理对比度的增加，但也配备了高级别的通道选择性地调整特定的对比度范围。
It is well known that prolonged observation of a high-contrast stimulus alters the perception of a subsequent test stimulus. Previous studies of perceived contrast shifts only reported perceived contrast reductions. Here, we used successive presentations of test and reference stimuli and found that perceived contrast was reduced if tests had a lower contrast than adaptors but was significantly enhanced when tests had a higher contrast than adaptors. Such bidirectional contrast aftereffects were not observed for single adaptor flashes but became increasingly pronounced for repeated adaptor presentations, thereby suggesting that the aftereffect is a consequence of adaptation rather than of attentional cuing or temporal repulsion. In addition, perceived contrast reduction weakened as we increasingly jittered the spatial position of the adaptor, but perceived contrast enhancement was observed for large spatial range of jittered adaptor positions. We conclude that aftereffects involve adaptation in distinct mechanisms with narrow and broad spatial tunings. Results suggest that the visual system not only possesses low-level contrast encoding units, which monotonically increase their responses as physical contrast increases, but is also equipped with high-level channels selectively tuned for particular contrast ranges.