Figure 4: Fine-to-coarse comparison for the AME with VarEn (a) and the AME with SampEn (b) for discriminating the Invisible (red circle) and the Visible conditions (blue triangle) over multiple scales. For the AME with VarEn (a), significant differences occur at the 1st–3rd scales, whereas for the AME with SampEn (b) significant difference only occurs at the 2nd scale. Conventions are the same as in Figure 3. The P values based on our VarEn and the SampEn along the fine-to-coarse scales are also compared (c), in which the horizontal black dotted line refers to the significance level ( ). Note that the P values greater than 0.35 are truncated.