Fig. 2: Procedure for experiment 1 and experiment 2.

a Experiment 1. The experiment was structured using a mixed design, incorporating color as a between-subject factor (encompassing color and black-and-white levels) and film editing as a within-subject factor (including happy, neutral, and fearful editing). The subplot provides an overview of the procedure for Experiment 1, which began with two practice trials. Each trial started with a 2-s display of a neutral face, followed by a 4-s presentation of an emotional scene, and concluded with a 2-s display of a similar neutral face. After the film sequence, participants rated the valence and emotional intensity of the neutral face within a 5-s response time. Each trial ended with a 1.5-s inter-trial interval (ITI). Notably, each condition included ten distinct film sequences. b Experiment 2. The experimental design was similar to that of Experiment 1. The subplot provides an overview of the procedure for Experiment 2, which began with two practice trials. Subsequent to these trials, participants underwent structural imaging before starting the formal fMRI experiment. Each trial consisted of a sequence starting with a 0.5-s crosshair sign, followed by a 2-s display of a neutral face, a variable jitter lasting 4 to 6 s, a 4-s emotional scene, another jitter, and concluding with a 2-s display of a similar neutral face. Then, a 0.65-s inter-stimuli interval (ISI) ensued. After each film sequence, participants were asked to rate the valence and arousal of the neutral face within a 5-s window. Each trial concluded with an ITI of 1 to 1.5 s. Each experimental condition comprised ten trials. This figure was produced by the authors. This figure was produced by the authors. This figure is covered by the Creative Commons Attribution 4.0 International License. Reproduced with permission of Yiwen Wang; copyright © Cao et al. all rights reserved.