The relation of phase noise and luminance contrast to overt attention in complex visual stimuli
The relation of phase noise and luminance contrast to overt attention in complex visual stimuli
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DOI：
10.1167/6.11.1
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发表时间：
2006-01-01
影响因子：
1.8
通讯作者：
Koch, Christof
中科院分区：
文献类型：
--
作者：
Einhaeuser, Wolfgang;Rutishauser, Ueli;Koch, Christof
注意模型通常基于低阶特征的差分图，而忽略了高阶刺激结构。高阶统计量在多大程度上影响人类对自然刺激的注意力？当观察者观看未修改和修改过的自然场景图像时，我们记录了他们的眼球运动。修改包括对比度调制（导致一阶和二阶统计量的变化），以及在傅立叶相位中添加噪声（导致高阶统计量的变化）。研究发现：(1)被试将刺激解释为户外场景的“自然”描述依赖于高度非线性、分类方式的高阶统计。(2)证实了先前的研究结果，在各种刺激类别中，注视位置的对比度都有所提高。此外，我们发现这个高度的大小取决于高阶统计量，并随着相位噪声的增加而减小。(3)对比度对高对比度眼位的整体调节，符合对比度对注视概率的线性影响。这种偏置与相位噪声无关。(4)无论相位噪声如何，局部对比度降低的小块对眼睛位置的排斥小于相同聚集面积的大块。我们的研究结果提供了证据，证明与周围统计数据的偏差，而不是对比本身，构成了对比与注视的既定关系的基础。
Models of attention are typically based on difference maps in low-level features but neglect higher order stimulus structure. To what extent does higher order statistics affect human attention in natural stimuli? We recorded eye movements while observers viewed unmodified and modified images of natural scenes. Modifications included contrast modulations (resulting in changes to first- and second-order statistics), as well as the addition of noise to the Fourier phase (resulting in changes to higher order statistics). We have the following findings: (1) Subjects' interpretation of a stimulus as a "natural'' depiction of an outdoor scene depends on higher order statistics in a highly nonlinear, categorical fashion. (2) Confirming previous findings, contrast is elevated at fixated locations for a variety of stimulus categories. In addition, we find that the size of this elevation depends on higher order statistics and reduces with increasing phase noise. (3) Global modulations of contrast bias eye position toward high contrasts, consistent with a linear effect of contrast on fixation probability. This bias is independent of phase noise. (4) Small patches of locally decreased contrast repel eye position less than large patches of the same aggregate area, irrespective of phase noise. Our findings provide evidence that deviations from surrounding statistics, rather than contrast per se, underlie the well-established relation of contrast to fixation.