健康与遗传心理学研究室知识库

反应抑制是指对优势的反应或习惯性行为的取消或克制，是个体适应环境的重要能力。近年来探讨情绪线索影响反应抑制的研究日益增多，但情绪线索对反应抑制的影响究竟是促进还是损害并没有一致的结论。对已有研究归纳分析发现，情绪线索对反应抑制的影响与情绪线索在反应抑制任务中出现的位置有关，当情绪线索能够增强对停止信号的觉察时情绪刺激可以促进反应抑制，而当情绪线索与抑制任务无关分散了注意力则会损害反应抑制。已有研究多关注情绪线索在启动、背景和反应试次位置时对反应抑制的影响，少有研究关注情绪线索出现在停止信号时的效应。根据对文献的总结，本研究假设停止信号位置的情绪线索会促进反应抑制。此外，临床群体如精神分裂症患者存在反应抑制的缺损，但精神分裂症患者对当下的情绪刺激知觉正常，提示情绪性的停止信号有可能促进其反应抑制能力。本研究将探讨两个科学问题。第一，当动作已经发生时，情绪性的停止信号对反应抑制的影响。第二，考察情绪性停止信号对精神分裂症患者反应抑制的影响。
本研究包括三个研究，研究一考察情绪面孔作为停止信号时对反应抑制的影响。研究一包括三个实验，所有被试均为健康大学生。实验一中（N=48），每个被试需判断出现的图形是圆形还是方形,看到形状中的快乐、愤怒、悲伤和中性面孔时则停止反应。这些面孔均去掉了头发、耳朵和颜色以减少与情绪无关的信息的干扰。实验二（N=30）优化了实验范式，增加了每种面孔图片的数量以避免被试对重复出现次数较多的图片产生情绪上的适应，同时去掉了悲伤面孔。实验三（N=30）提高了实验二中面孔图片在情绪表达上的生态效度，保留所有了面孔的颜色、头发和耳朵。以上三个实验的的结果均发现情绪面孔停止信号对反应抑制无显著影响。
研究二采用和研究一相似的停止信号任务，选取了受文化因素影响少的情绪诱发图片作为停止信号, 所有被试是健康大学生。在实验四（N=25）中，被试需要判断出现的图形是直线还是曲线方形，看到方形中的情绪图片则停止反应。结果发现，负性情绪图片对反应抑制有损害作用，正性情绪图片对反应抑制无显著影响。实验五（N=27）缩短了实验时长以应用于临床研究，缩短试次间隔后重复了实验四的结果。实验六（N=24）将实验五中血腥暴力的负性情绪图片更换为内容相对温和的负性图片以适用于临床群体, 结果发现唤醒度较低的负性情绪图片对反应抑制无显著影响。实验七（N=23）将之前组块设计的停止信号任务改为混合设计，让不同情绪类型的图片在同一组块中交替呈现，结果发现负性情绪图片对反应抑制反而有促进作用，正性情绪对反应抑制仍然没有显著影响。
研究三考察了情绪线索对精神分裂症患者反应抑制的影响。36名社区精神分裂症患者和36名性别、年龄和教育年限上匹配的健康成年人完成了与实验七相同范式的情绪图片停止信号任务。结果发现，负性情绪图片的停止信号不仅能够促进精神分裂症患者的反应抑制，且促进效应与健康对照组相似。正性情绪图片对两组被试的反应抑制均无显著影响。精神分裂症患者的反应抑制能力有显著的缺损，表现为更长的反应抑制时间和更低的抑制成功率。尽管负性情绪图片对精神分裂症患者的反应抑制有促进作用，但患者在三种线索条件下仍然存在缺损，且缺损大小相似，说明负性情绪图片对反应抑制的促进作用有限，无法使精神分裂症患者的反应抑制能力达到与健康被试相同的水平。此外，精神分裂症患者在负性停止信号之后的按键反应正确率低于中性和正性条件。说明负性线索对反应抑制的促进作用对注意资源的损耗较大,而这种损害作用在健康对照组中并没有出现。
本研究系统地考察了包含情绪线索的停止信号对健康群体和精神分裂症患者反应抑制的影响，有三个主要发现。首先，在研究一和研究二中对健康群体的实证研究发现，负性情绪图片作为停止信号对反应抑制的影响与情绪图片的唤醒度和实验范式设计有关。在组块设计中，高唤醒度的负性情绪图片会损害反应抑制，中等唤醒度的负性情绪图片对反应抑制无影响。在混合设计中，中等唤醒度的负性情绪图片会促进反应抑制。其次，在组块和混合设计中，正性情绪停止信号对反应抑制都没有影响。最后，负性情绪图片停止信号对精神分裂症患者反应抑制能力的促进作用与健康对照相似，但会损耗较多的认知资源，且患者的反应抑制能力在情绪线索条件下仍然存在缺损，无法达到和健康对照相似的水平。
目前，对情绪线索如何促进反应抑制的研究较少，本研究的发现表明情绪线索既可能促进也可能损害反应抑制，具体的效应与实验设计和情绪材料的选取密切相关。这些结果说明了情绪线索作为停止信号时对反应抑制的影响较为复杂，体现了情绪和认知控制之间复杂的交互关系。其次，本研究创新性地将情绪线索促进效应应用于精神分裂症患者，发现中等唤醒度的负性图片作为停止信号时可以促进精神分裂症患者的反应抑制能力，这一发现为临床干预提供了一定的理论基础。

Response inhibition refers to an ability to cancel or restrain an advantage response or habitual behavior, and it is an important ability for individuals to adapt to the environment. In recent years, the research of emotional effect on response inhibition has been increasing, but whether emotional cues facilitate or impair response inhibition was inconclusive. Based on existing evidence, the influence of emotional cues on response inhibition is related to the position of emotional cues in a response inhibition task. When the emotional cue enhances attention of a stop signal, the response inhibition is improved, whereas inhibition is impaired when the emotional cue is unrelated to the inhibition task. Most studies in the field have focused on the effects of emotional cues on response inhibition when the cues were in the priming, background and go trial positions, but fewer studies investigated the effect when emotional cues are as stop signals. Based on the summary, we predict emotional stop signals enhances inhibition in healthy group. In addition, clinical group such as patients with schizophrenia often show impairment in response inhibition. However, the patients with schizophrenia usually have normal emotional response when perceiving an emotional stimulus, therefore emotional stop signals may improve response inhibition in patients with schizophrenia. The two research questions were investigated in the present study. First, the influence of emotional stop signal on response inhibition was examined, and a benefit was predicted. Second, we examined whether patients with schizophrenia would also show benefit of emotional stop signals on response inhibition.
There were three studies. In series of three experiments in Study 1, the effect of emotional facial stop signals on response inhibition was examined in university students. In Experiment 1 (N=48), participants were asked to judge whether the shape was a circle or a square and made responses, and they need to stop response whenever they saw a face (i.e., stop signal). The four types of faces were happy, anger, sadness, or neutral, and the hair, ears and color of the face were removed to reduce interference unrelated to emotion. In Experiment 2 (N=30), more faces of different identities were included to avoid emotional adaptation of frequently repeated faces. In Experiment 3(N = 30), the ears, hair and colors of the faces were kept to improve the ecological validity of emotional faces. Across the three experiments, there was no significant effect of emotional faces on response inhibition.
In Study 2, a similar stop signal task was used except that emotional pictures were used as stop signals to reduce the cultural difference in facial perception. All the participants were healthy university students. In Experiment 4 (N = 25), participants were asked to judge whether a square was linear or curvy and made responses, and they had to stop response when they saw a picture inside the square. The picture cues were negative, neutral or positive. Negative cues impaired the inhibition while positive cues had no effect. In Experiment 5 (N = 27), the inter-stimuli-interval was shortened in the stop signal task to make it compatible with clinical studies, and it replicated the findings in Experiment 4. In Experiment 6 (N = 24), the negative pictures with violent content in previous experiments were replaced with the pictures without such content to prepare for clinical research, the new pictures had lower arousal ratings and failed to show any significant influence on response inhibition. In Experiment 7 (N = 23), the block design in previous experiment was changed to mixed design with positive, negative and neutral picture cues appearing alternately in the same block. Surprisingly, the negative emotional pictures facilitated response inhibition, and positive pictures still had no effect on response inhibition.
In Study 3, the influence of emotional cues on response inhibition was examined in patients with schizophrenia. A total of 36 patients with schizophrenia from community and 36 healthy controls matched in gender, age and education years attended the experiment. The task was same as the paradigm that showed a benefit of negative stop signals on response inhibition. The negative emotional pictures facilitated response inhibition in patients with schizophrenia to the same extent as to healthy controls. In both groups, positive pictures had no effect on inhibition. Despite benefit of negative stop cues, patients with schizophrenia still had worse performance of inhibition compared to health controls. Moreover, patients with schizophrenia had lower response accuracy of response trials after the stop trials in the condition negative cues, indicating the benefit of negative cues for response inhibition has a cost on cognitive resources.
In sum, present study systematically examined the effect of emotional stop signals on response inhibition in healthy group and patients with schizophrenia. There were three main findings. First, the findings of Study 1 and 2 in healthy undergraduates indicates that the influence of negative picture stop signals on response inhibition depends on arousal level of the picture cues and experiment design. In block design, highly arousal pictures impaired response inhibition whereas moderately arousal negative pictures had no effect. In mixed design, moderately arousal negative pictures facilitated response inhibition. Secondly, in both block and mixed design, positive stop signals had no effect on response inhibition. Finally, negative pictures facilitated inhibition in patients with schizophrenia to a similar extent as to healthy controls, but the impairment of inhibition still occurred in conditions of negative cues.
The studies of the influence of emotional stop cues on response inhibition are limited. The findings of present study indicate that emotional stop signal may facilitate or impair response inhibition, which depends on the experiment design and the arousal of emotional cues. These findings suggest that the effect of emotional cues on response inhibition are relatively complex, reflecting the intricate interaction between emotion and cognitive control. Moreover, the finding that moderately arousal negative stop signals improved response inhibition in patients with schizophrenia, may provide theoretical basis for clinical interventions in the future.