Modulatory Effects Of Disgust And Fear Stimulus On The Early Attention Processes:The Effect Of Arousal

Attention processing of potential dangerous information in the environment always been the focus topics in the field ofevolutionary psychology.Priority processing to stimulus that are threatening or with threat signal has evolutionary adaptability from evolutionary perspective.As typical negative emotions,disgust and fear indicate potential threat of the environment,and have the significance to promote individual adaptation,and human survival. However, there are some inconsistent results in previous studies which focused on the attention processing of fear- and disgust-evoking stimuli.Therefore, this study designed three experiments to clarify the influences of disgust and fearstimulus on the early attention processes.First of all, the "pure" disgusting and fearful pictures were selected from the International Affective Picture System(IAPS), Chinese Affective Picture System(CAPS) and the internet,which were selected for subsequent experiments by independent material evaluation experiment. Two experiments were designed to identify the modulatory effects of disgust and fear stimuli on early attention processes.Based on research results and adopted the covert orienting paradigm and fear- and disgust-evoking stimuli of moderate arousal were adopted in the experiment 1. Participants were asked to identify a target which was briefly presented( 50ms) around a central image cue, which could either be disgusting,frightening, or neutral. The interval between cue onset and target presentation varied within three blocks, allowing us to investigate the time course of attention engagement.Reaction times were longer when targets quickly(200 ms) followed disgust-evoking images than when they followed neutral- or fear-evoking images. For the other, longer interval conditions no significant image effects were found. These results suggest that emotion attention effects can be found at very early visual processing stages and that only disgust-evoking images, and not fear-evoking ones, keep hold of our attention for longer. The interesting piont is,this effect is independent by individual’s characteristics of the trait or state anxiety and disgust sensitivity.In the experiment 2,the adjusted dot probe paradigm(Koster et al., 2004, 2006)was adopted,and on the basis of Experiment 1, the high and low arousal level of pictures was increased, to test whether the modulatory effects of disgust and fear stimulus on the early attention processes effected by its arousal level.The results verify the influences of arousal level. High arousal level of disgusting and fearful images both modulated the early attention processes.Finally, this study draws the conclusions as following.In evoked "pure" emotional stimulus condition, the modulatory effects of disgust and fear stimulus on the early attention processes effected by its arousal level:(1)in moderate levels of arousal condition, only the disgusting stimulus modulate the early attention;(2)and in high arousal level, disgusting and fearful stimulus both modulated the early attention processes;(3)and the modulatory effects performance forindividuals difficulty to disengage of disgusting and fearful stimulus;(4) and the effect is independent by individual’s characteristics of the trait or state anxiety and disgust sensitivity.The results verify that the modulation of disgusting and fearful images on the early attention,were effected by it’s arousal level.