Fig. 2: The relationship between camouflage and natural or checkerboard backgrounds.
From: The dynamics of pattern matching in camouflaging cuttlefish
a, The correlation between camouflage patterns and natural background images in skin-pattern space (stimuli N0–N29; n = 3 animals, >8 trials per stimulus; Methods). PC1 (accounting for 17.5 ± 0.8% of the variance) shows significant stimulus–response correlation (Pearson’s r = 0.62, 0.64, 0.54; P < 10−22). In the three analysed animals, the first 3 (animal S205), 3 (animal S206) and 2 (animal S207) PCs are significantly correlated (35.8 ± 5.1% variance, Pearson’s r = 0.56 ± 0.05, P < 10−15). b, Skin patterns evoked by checkerboards of different spatial frequencies (square sizes, 0.04–20 cm, only 0.08–10 cm shown) reveal a monotonic gradient of intermediate responses. PC1 shows a statistically significant stimulus–response relationship within the shaded region (0.31–1.25 cm; linear regression r2 = 0.50 ± 0.04, P ≤ 0.0001; n = 3 animals, 4–8 trials per stimulus). In the three analysed animals, the first 4 (animal 1), 2 (animal 2) and 4 (animal 3) of the top 50 PCs are statistically significant (r2 = 0.40 ± 0.03, P ≤ 0.0001). The error bars show the 95% confidence intervals. c, Four clusters of co-varying chromatophores (components), of which the state depends positively (red) or negatively (blue) (P ≤ 0.05) on the stimulus, in one representative animal of three analysed. n = 4–8 trials per stimulus. Each point represents the mean steady-state response sampled at 25 Hz over 46 s. Top, cluster locations. Bottom, correlations between the mean chromatophore area and checkerboard period.
