Repetition Priming Of Emotional Stimuli

The goal of the present study is to investigate emotional modulation of repetition priming. Current study included three experiments, with Experiment 1 and 3 as behavioral studies and Experiment 2 as an fMRI study. In a standard repetition priming paradigm, Experiment 1 used personality traits with different valence as materials to study the behavioral priming modulated by negative emotion. Using the same paradigm and materials as Experiment 1, Experiment 2 adopted an event-related fMRI design to investigate neural mechanism underlying the behavioral priming modulated by negative emotion. Experiment 3 further tested repetition priming modulated by negative emotion with negative pictures as materials. Positive pictures were also employed in the experiment to investigate repetition priming of different emotional pictures. And in experiment 3, novel, low-primed and high-primed items were distinguished according to the number of presentations in order to examine whether the number of repetitions influence emotional modulation of repetition priming. The results are as follows:1. Combining the behavioral data from Experiment 1 and Experiment 2, the results revealed significant higher repetition priming of neutral stimuli than that of negative stimuli, indicating that negative stimuli are resistant to repetition priming.2. fMRI results in Experiment 2 revealed that, on one hand, repetition suppression in regions engaging in perceptual priming (visual areas and fusiform gyrus) were not significant for negative stimuli but significant for neutral stimuli, indicating that at least in the perceptual level, people would not simplify the processing for negative stimuli just after several repeated contacts. On the other hand, there was significant repetition suppression in right inferior frontal gyrus for negative stimuli, suggesting that negative emotion may enhance the perceptual priming of stimuli at a certain extent. 3. In experiment 3, low-priming and high-priming revealed a different influence on the repetition priming of neutral, negative and positive pictures. In low-priming condition, there were no significant differences among the mount of repetition priming of three different emotional pictures. In high-priming condition, the mount of repetition priming of negative and positive pictures was significant lower than that of neutral pictures respectively, and no significant difference was found between negative pictures and positive pictures.