关键词: 核心厌恶, 道德厌恶, 适应性, 主观情绪体验, 自主神经活动

Abstract: Abstract: Disgust has been considered as one of six basic emotions that has the adaptive function to protect us from the harmful substances. Previous studies have shown that disgust is accompanied by increased parasympathetic responses. However, opposite results have been reported. Different types of elicitor may have contributed to existing contradictory findings. A wide range of stimuli can evoke disgust. Core disgust refers to the original form of disgust, triggered by potentially toxic visual, gustatory, or olfactory stimuli that could contaminate the body (i.e., contaminated foods). Moral disgust seems unique to humans, triggered by the violation of moral values or socially inappropriate people and behaviors. It is generally assumed that core disgust serves a disease-avoidance function by facilitating rejection and avoidance of contamination-related stimulus, while moral disgust play an important role in the regulation of social behavior and is crucial for maintenance of social norms. The evolutionary adaptation theory holds that disgust has evolved from the antecedent distaste response and different types of disgust originate from core disgust. Empirical studies on the homogeneity and heterogeneity between core and moral disgust are sparse and inconsistent. There has been increased debate concerning whether disgust reactions elicited by different types of elicitor have the common origin. The major aim of the present study was to explore whether core and moral disgust may dissociate in their affective self-reports and response patterns of the autonomic nervous system, as well as the time-course of emotional responses. Laboratory psycho-physiological experiment was conducted to examine subjective and physiological responses to disgust-evoking pictures. 32 female university students (16 in the core disgust group and 16 in the moral disgust group) were tested individually in a quiet testing room, with each participant session lasting around 40 mins. Disgust pictures were presented to each participant in a random order via Super Lab system on a monitor screen. Automatic physiological responses were collected continuously by Biopac MP150 physiological recording system. The skin conductance, heart rate and heart period variability were recorded and analyzed. Participants were shown 10 pictures at four different time points to explore the emotional arousal and development of two types of disgust. The experiment used a two-factor repeated measures design of 2 (group: core disgust and moral disgust)?2(stage: 0, 2, 4, and 6min), in which the group was the between-subjects design and the stage was the within-subjects design. Within each disgust condition, 10 pictures were presented and each picture lasted for 10s on the screen. Participants were asked to rate the intensity of each emotion (happiness, sadness, anger, disgust, and fear) before and immediately after exposed to disgust pictures on a scale of 1-7(where 1 indicated an absence of that emotion and 7 indicated strong intensity). Repeated Measures ANOVAs were used to analyze the subjective, electrodermal and cardiovascular reactions of core and moral disgust. The results showed that core and moral disgust pictures used in this study generated similar overall levels of subjective disgust reaction. Both types of disgust were concomitant with other negative emotions. Core disgust elicitors generated more fear, whereas sociomoral stimuli evoked more angry and sad. The disgust-induced subjective responses were associated with different patterns of autonomic reactivity. Core disgust increased high frequency component of heart period variability and sociomoral disgust increased heart rate. Moreover, responses to core and sociomoral disgust elicitors varied in different ways over time. Participants experienced decreased disgust when core disgust elicitors repeatedly presented and a decrease in high frequency component of heart period variability was observed. Repeated exposure to sociomoral disgust elicitors increased skin conductance responses, while self-reported disgust response seemed more resistant to change over time. Taken together, these results suggested that core disgust and moral disgust are separate emotions, appears to elicit heterogeneous subjective and autonomic reaction.

Key words: Core disgust, moral disgust, adaptation, subjective emotional experience, autonomic nervous activity