The Mechanism Of The Impact Of Emotional Stimulus On Location Negtive Priming

The negative priming (NP) refers to the slowing of a response to an item that has previously been ignored, and is the opposite of the positive priming or facilitating of responses observed following the repetition of previously attended stimuli. During the last 30 years, the negative priming has been widely used as a task to investigate the mechanism of selective attention. There are two kinds of negative priming:identity negative priming and location negative priming. The location negative priming is an established tool for the investigation of location selective attention in behavioral experimental psychology. Exploring the mechanism of the impact of different emotional and facial stimulus on location negative priming makes great contribution to theory about the interaction between emotion and cognition (such as inhibition and selective attention). The present study investigated the neural mechanism of location negative priming, the influences of facial and non-facial stimulus on location negative priming, the different impacts of different emotional faces on location negative priming and the discrepancy between the impacts of different emotional faces on location negative priming in the time course and intensity using event-related potential technology.The study included two experiments. In experiment one, we investigated the influences of facial and emotional stimulus on location negative priming. Mosaic and three kinds of expression pictures were used as the distractors. The location negative priming task was conducted to study whether the location negative priming can be affect by different distractors. And the influence of gender and RSI were also been investigated. The results showed the location negative priming was variable under two RSI levels. When RSI was short, the negative priming effect of facial stimulus disappeared because the attentional bias to faces. But the negative priming effect of mosaic pictures was significant. However, when RSI was long, the negative priming effects of mosaic pictures, neutral and happy expressions were all disappeared. The negative priming effect of fear expression was significant because the intense avoidance to fear faces. Besides, the gender effect was marginally significant, it seemed that the interaction mentioned above was significant for female rather than male.In experiment two, we measured the location negative priming when the RSI was 1200ms and different emotional faces were used as the distractors in the phase of prime. On the one hand, our purpose is to investigate the cognitive and neural mechanism of location negative priming. On the other hand, we want to study the neural mechanism of the impacts of different emotional distraction stimulus in prime phase on location negative priming. The behavioral results was consistent with experiment one. The ERP results showed the emotional effects of N170, VPP, N2 and P3 components during the phase of prime were all significant. And during the phase of probe, the P3 component was larger under negative priming condition than under control condition. Besides, the interaction between emotion and priming was significant. When the distractor was fear expression, the N2 component was more negative under control condition than negative priming condition. The amplitude of P3 under negative priming condition was also larger than control condition when fear expression was used as distraction picture. Analysis of the average amplitudes of the difference wave between negative priming and control condition (300-500 ms) has been conducted. The interaction of emotion and electrode was significant. At some electrodes, the average amplitudes were larger under negative priming condition than control condition when fear faces were presented as the distraction pictures.In conclusion, the negative priming effect was significant in present study and could be influenced by RSI, gender and the distractors. Especially, under different RSI, different distractors could induce different negative priming. When RSI was short, the negative priming effect could disappear because the attentional bias to faces. When RSI was long, subjects have enough time to inhibit the interference of fear expression and avoid the fear expression because fear face was threatening stimuli. The ERP results showed during the phase of prime, location selective attention can be modulated by emtion within 100-250ms of the stimulus onset. During the phase of probe, emotion can influence the N2 and P3 components. The first component has proved the inhibition mechanism of negative priming. And the second has proved the episodic retrieval model. In addition, compare to neutral and happy expression, when distraction stimuli was fear faces, the differences between negative priming and control condition of probe-N2 and probe-P3 were significant, which explained the neural mechanism under the impact of emotion on negative priming effect.