The Search Asymmetry Of Schematic Emotional Faces:Emotional Or Perceptional?

The search asymmetry effect of emotional face was defined as that a negative (anger, sad) target face is found faster among positive (happy) distractor faces than a positive target face among negative distractor faces.There are mainly two viewpoints to explain the search asymmetry effect:emotional perspective and perceptual perspective. On the viewpoint of emotional perspective, emotion is the explaination of search asymmetry effect. Threat capture hypothesis and emotional disengagement hypothesis are the main viewpoint of emotional perspective. While the perceptual perspective attribute the search asymmetry effect to the difference of perceptual features. The perceptual grouping account and the closure account are the main viewpoint, including the difference of other facial features.Through the analysis and comparison of the existing theories, the research found that researchers tend to explain the search asymmetry effect of emotional face on one side of emotional or perceptual perspective without taken both of them into consideration. Actually, no matter what people observed is the real faces or the schematic faces, they can both perceive the emotional content and perceptual features, and could not ignore their co-existence. Therefore, the integration of existing theories in order to explain the search asymmetry effect is necessary. This study has proceeded a series of experiments through the separation of emotional factors and perceptual factors.First, the study has proceeded to weaken the perceptual difference of positive face and negative face to investigate the role of emotion.In experiment1, the research used positive and negative schematic faces that were self-made to replicate previous researches. The experiment adopted visual search paradigm to test16subjects, the result showed a significant search asymmetry effect, which means it was faster to response to a negative target face than a positive target face.In experiment2, the contour of the schematic faces was changed into square, then the closure feature was existed in both of positive and negative face but without parallel feature. After a visual search task, the result showed a significant search asymmetry effect, which suggested the role of emotional factors through analysis.In experiment3, the contour of the schematic faces was removed to weaken the perceptual features further. Then both closure and parallel features were eliminated in positive face and negative face. After a visual search task, the result showed a significant search asymmetry effect, which suggested the dominated role of emotional factors through analysis and comparison between experiments.Without contours in experiment3, the confusion between eyes and mouth of the schematic face could happen. So in experiment4, the study added a pair of eyes on the face of experiment3, the result showed that subjects could easily perceived it as expressions. After a visual search task showed a significant search asymmetry effect, and there is no difference between experiment3and experiment4, which confirmed the analysis in experiment3.In experiment5, the study only retained the mouth and the chin lines, but the relation between the stimulus and emotional face were informed to subjects through the animation before the experiment. Then after a visual search task, the result showed a significant search asymmetry effect. This effect may be the mixture of emotional and perceptual factors based on the perceptual grouping hypothesis.Next, on the basis of the role of emotional factors, the research has proceeded to weaken the emotional content of schematic faces to investigate the role of perceptual factors.In experiment6, the experimental material was the same as experiment5, but none emotional information was informed to subjects before the task. A significant search asymmetry effect was observed after a visual search task. Analysis and comparison with experiment5could suggested the role of emotion in experiment5, and the pure role of perception in experiment6, which could be explained by perceptual grouping.In experiment7, the study just retained the mouth lines of positive and negative face as the stimulus, which have no relationship with emotion, but the search asymmetry effect was also observed after a visual search task, which revealed the difference between upward curved lines and downward curved lines could attribute to this effect.In previous experiments, the search array was arranged in matrix. In order to exclude the effects of spatial configuration, the study varied the search array into a random array in experiment8, after a visual search task, the result still showed a search asymmetry effect, which exclude the effect of spatial configuration and the search array.For exclude the effect of spatial configuration further, the study arranged the search array in circle in experiment9. Although the search asymmetry effect was just reached a marginal level, it did not cover the difference between the two kinds of lines.Through a series of experiment and analysis, the research suggested that the emotional factors and perceptual factors were both attribute to the search asymmetry effect of emotional faces.