Does conspicuousness scale linearly with colour distance? A test using reef fish.
Does conspicuousness scale linearly with colour distance? A test using reef fish.
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显着性是否与颜色距离成线性关系？
DOI：
10.1098/rspb.2020.1456
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Santiago C
中科院分区：
文献类型：
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作者：
Santiago C
为了有效，动物颜色信号必须引起注意，因此需要引人注目。为了理解信号功能，评估它们在各种环境条件下对相关观看者的显着性是有用的，包括当视觉场景被不同颜色的物体弄乱时。一种广泛使用的色差 (ΔS) 度量基于受体噪声限制 (RNL) 模型，该模型最初是为了确定两种相似颜色何时出现彼此不同而提出的，称为辨别阈值（或只是显着差异）。对超过此阈值的颜色之间的感知距离的估计（称为“超阈值”色差）通常假设颜色的显着性与颜色距离成线性比例，并且该比例与颜色空间中的方向无关。目前，几乎没有行为证据支持这些假设。本研究使用珊瑚礁鱼Rhincanthus aculeatus 进行石原式测试，评估了超阈值颜色中Δ沙的显着性之间的关系。作为我们衡量显着性的指标，我们测试了当呈现两个彩色目标时，鱼是否更喜欢啄食与平均干扰物颜色相比具有更大 ΔS 的目标。我们发现 ΔS 和显着性之间的关系遵循 S 形函数，高 ΔScolours 被认为同样显眼。我们发现 ΔS 和显着性之间的关系在不同的颜色空间（即不同的色调）中有所不同。 S 形可检测性曲线几乎不受背景颜色变化或使用不包含受体噪声的模型计算颜色距离的影响。这些结果表明，即使在复杂的观看环境中，RNL 模型也可以为小阈上距离颜色的感知距离提供准确的估计，但在感知距离超过 10 ΔS 时必须谨慎使用。
To be effective, animal colour signals must attract attention—and therefore need to be conspicuous. To understand the signal function, it is useful to evaluate their conspicuousness to relevant viewers under various environmental conditions, including when visual scenes are cluttered by objects of varying colour. A widely used metric of colour difference (ΔS) is based on the receptor noise limited (RNL) model, which was originally proposed to determine when two similar colours appear different from one another, termed the discrimination threshold (or just noticeable difference). Estimates of the perceptual distances between colours that exceed this threshold—termed ‘suprathreshold’ colour differences—often assume that a colour's conspicuousness scales linearly with colour distance, and that this scale is independent of the direction in colour space. Currently, there is little behavioural evidence to support these assumptions. This study evaluated the relationship between ΔSand conspicuousness in suprathreshold colours using an Ishihara-style test with a coral reef fish,Rhinecanthus aculeatus. As our measure of conspicuousness, we tested whether fish, when presented with two colourful targets, preferred to peck at the one with a greater ΔSfrom the average distractor colour. We found the relationship between ΔSand conspicuousness followed a sigmoidal function, with high ΔScolours perceived as equally conspicuous. We found that the relationship between ΔSand conspicuousness varied across colour space (i.e. for different hues). The sigmoidal detectability curve was little affected by colour variation in the background or when colour distance was calculated using a model that does not incorporate receptor noise. These results suggest that the RNL model may provide accurate estimates for perceptual distance for small suprathreshold distance colours, even in complex viewing environments, but must be used with caution with perceptual distances exceeding 10 ΔS.