Page 145 - Demo

Absence of cognitive bias to flanges in orang-utans1436or small flange picture had no robust effect on the RT of Kawan (bcongruent = -3.28 [8.50], 89% CrI [-16.66; 10.49], pd = 0.65), Samboja (bcongruent = 3.90 [9.38], 89% CrI [-10.68; 19.25], pd = 0.66), and Sandy (bcongruent = 2.08 [9.13], 89% CrI [-13.05; 16.52], pd = 0.59). We also found no robust effect of probe location (left/right) on RT, indicating that Kawan (bleft = 5.08 [8.66], 89% CrI [-9.05; 18.41], pd = 0.72), Samboja (bleft = -6.61 [9.41], 89% CrI [-21.82; 8.60], pd = 0.76), and Sandy (bleft = 7.58 [9.30], 89% CrI [-7.33; 22.12], pd = 0.80) did not have a side bias. Figure 3 – Posterior predictions of the difference in RT between trials where the probe replaced (A) the stimulus with larger flanges (Congruent) and trials where the probe replaced the stimulus with smaller flanges (Incongruent), or (B) replaced the stimulus with symmetrized face (Congruent) and trials where the probe replaced the stimulus with original face (Incongruent). Values under the horizontal null-line mean that the subject was predicted to respond faster to congruent than incongruent trials.SymmetryIn the symmetry dot-probe, we found no attentional bias for symmetrical faces in any of the three participating orang-utans (Figure 3B; Supplementary Table 2; see Appendix G for model stability checks); whether the probe replaced the large or small flange picture had no robust effect on the RT of Kawan (bcongruent = -3.28 [8.50], 89% CrI [-16.66; 10.49], pd = 0.65), Samboja (bcongruent = 3.90 [9.38], 89% CrI [-10.68; 19.25], pd = 0.66), and Sandy (bcongruent = 2.08 [9.13], 89% CrI [-13.05; 16.52], pd = 0.59). Similar to the flange size experiment, we found no robust effect of Tom Roth.indd 143 08-01-2024 10:41