Affective Priming Effects Of The Two Hemispheres Of The Brain

The valence hypothesis proposes that the right hemisphere in the processing of negative emotions play a leading role, while the left hemisphere is mainly responsible for the processing of positive emotions.The affective priming paradigm was used in this experimental research. Experimental materials are pictures of Chinese emotional faces. The prime stimuli were negative stimuli (sad faces), positive stimuli (happy faces), and plain gray images, and the target stimulus is neutral face pictures. Prime stimuli were briefly presented in the left visual fields or the right visual fields of the subjects, and then presented in the same position a mosaic picture as mask. Target stimuli were presented in the center of the screen. Subjects were asked press the corresponding key as response to the target neutral faces. And they were required to make their judgments by intuition, under the first impression. The subjects were 54 graduate students in the school, of which 26 were boys and girls 28. The study is divided into two experiments. In the first experiment, the prime time was 25 ms, and in the second was 50ms.Study found that there was a significant main effect of vision when prime time was 25ms(F(1,52)=15.10,p<0.01). Compared with priming in the left visual fields, the subjects showed more preference for the target when priming in right visual fields. There was a significant interaction of primexvisual field(F(2,51)=10,18,p<0.01).When prime time was 50 ms, the prime stimuli's impacts on preferences were significant(F(2,51)=6.48, p<0.05), compared to the negative prime group, the subjects showed more preference for the target when priming positively. There was a significant interaction of primexvisual field(F(2,51)=3.05,p<0.05).In addition, whether prime time was 25 ms, or 50 ms, subjects showed more preference for the target neutral face when the plain gray pictures presented in the right visual fields, compared to presented in the left visual field.The results showed that there was division of labor between the left and right hemisphere during emotional processing. While the right hemisphere was mainly responsible for the negative emotion, the left was mainly for the positive ones. However, there was also cooperation between the left and right hemispheres, especially when the emotional stimuli was above the threshold level. In conclusion, this study provides some support for the valence hypothesis from the perspective of behavioral experiment. But the same study also found that it was not absolutely that the left hemisphere is responsible for positive emotion, the right hemisphere is responsible for negative emotions. There was also some degree of cooperation between the two hemispheres in the processing of emotions, when the prime time was as long as 50ms.