Animal detection and identification in natural scenes: Image statistics and emotional valence
Animal detection and identification in natural scenes: Image statistics and emotional valence
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DOI：
10.1167/12.1.25
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发表时间：
2012-01-01
影响因子：
1.8
通讯作者：
Einhaeuser, Wolfgang
中科院分区：
文献类型：
--
作者：
Naber, Marnix;Hilger, Maximilian;Einhaeuser, Wolfgang
人类快速而准确地处理自然场景。低层次的图像特征和情感效价影响这样的处理，但大多是孤立地研究。这些因素在哪个加工阶段起作用，以及它们如何相互作用，在很大程度上仍然没有得到解决。在这里，我们简要介绍了自然图像，并要求观察者报告动物的存在或不存在（检测），检测到的动物的物种（识别），以及他们的信心。在第二个实验中，同样的观察者根据他们的情绪影响对图像进行评级，并在想象与所描绘的动物的真实遭遇时估计他们的焦虑。我们发现，随着图像亮度、背景对比度、动物饱和度以及目标与背景之间的亮度加颜色对比度的增加，检测和识别得到改善。令人惊讶的是，与较低焦虑相关的动物被更快地检测到，并以更高的信心被识别，情绪影响比焦虑更能预测表现。瞳孔大小与图像呈现后不同时间点的检测、识别和情绪效价判断相关。值得注意的是，威胁性动物的图像会导致瞳孔变小，平均焦虑等级较高的观察者平均瞳孔较小。总之，快速视觉处理取决于目标和背景特征之间的对比，而不是整体视觉环境，受到焦虑的负面影响，并发现其处理阶段差异反映在瞳孔反应中。
Humans process natural scenes rapidly and accurately. Low-level image features and emotional valence affect such processing but have mostly been studied in isolation. At which processing stage these factors operate and how they interact has remained largely unaddressed. Here, we briefly presented natural images and asked observers to report the presence or absence of an animal (detection), species of the detected animal (identification), and their confidence. In a second experiment, the same observers rated images with respect to their emotional affect and estimated their anxiety when imagining a real-life encounter with the depicted animal. We found that detection and identification improved with increasing image luminance, background contrast, animal saturation, and luminance plus color contrast between target and background. Surprisingly, animals associated with lower anxiety were detected faster and identified with higher confidence, and emotional affect was a better predictor of performance than anxiety. Pupil size correlated with detection, identification, and emotional valence judgments at different time points after image presentation. Remarkably, images of threatening animals induced smaller pupil sizes, and observers with higher mean anxiety ratings had smaller pupils on average. In sum, rapid visual processing depends on contrasts between target and background features rather than overall visual context, is negatively affected by anxiety, and finds its processing stages differentially reflected in the pupillary response.