Page 86 - Demo

Chapter 484ProcedureThe experiment involved a dot-probe paradigm, similar to Experiment 1. Participants performed 60 trials, consisting of 20 trials of three different combinations (i.e., symmetrical-original, asymmetrical-original, symmetricalasymmetrical). Within each combination, the probe appeared 10 times behind each category, and the location of the probe was balanced. Participants were only presented with pictures of opposite-sex individuals. The participants’ RT to the probe was the dependent variable for our analyses.Statistical AnalysesWe first excluded extremely fast and slow reactions times, following the same method as described for Experiment 1. The lower and upper filter resulted in exclusion of 524 of 9,000 trials (6.24%). We further excluded two subjects because the filtering criterion resulted in more than 25% of their responses being excluded. Therefore, the final data set contained 7,789 trials of 138 participants (67 females).Our statistical methods were similar to those described for Experiment 1, with a few exceptions. To test our hypothesis, we created a model that used by-subject mean-centered RT as the dependent variable and the interaction between condition (symmetrized vs. original, asymmetrized vs. original, symmetrized vs. asymmetrized) and probe location (behind symmetrical/behind asymmetrical face). Furthermore, in contrast to Experiments 1 and 3, this experiment did not include a stimulus validation.ResultsSimple ModelTo test our main prediction that facial symmetry would significantly influence RT, we ran a Bayesian mixed model with by-subject mean-centered RT per trial as the dependent variable and the interaction between condition and Probe Location as independent variables (Table 2; see Appendix G for model stability checks). We found no effect of facial symmetry on RT in any of the three conditions (Figure 4); in each condition, the differences in RT between the probe locations were negligible (asymmetrized vs. original: median difference = −1.01 [3.05], 89% CI [−5.92, 3.82], pd = .63; symmetrized vs. original: median difference = .99 [2.91], 89% CI [−3.69, 5.66], pd = .64; symmetrized vs. asymmetrized: median difference = 1.67 [2.97], 89% CI [−3.14, 6.32], pd = .71).Tom Roth.indd 84 08-01-2024 10:41