情绪状态对条件化恐惧及恐惧相关线索记忆的影响

Effects of emotion state on conditioned fear response and memory for conditioned fear cues

目的探讨积极与消极情绪状态对条件化恐惧反应及恐惧相关线索记忆的影响。方法招募48名在读本科生作为本研究被试。第1天(Day1),在无情绪诱导的情况下,以强噪音作为无条件刺激,以动物或果蔬图片作为条件化刺激,对48名被试进行条件化恐惧习得训练;第2天(Day2),所有被试按男女比例匹配的原则分为三组:中性组(n=16)、积极组(n=16)、消极组(n=16)。先利用中性、积极与消极情绪视频诱导三组被试分别产生不同的情绪状态,再进行与第1天相同的条件化恐惧习得训练。第3天(Day3),随机呈现动物或果蔬图片,考察被试对条件化恐惧线索的皮肤电反应及再认率。结果积极组被试对条件化恐惧线索的皮肤电反应在情绪诱发后[(0.091±0.026)μs]低于情绪诱发前水平[(0.148±0.027)μs],差异有统计学意义(P<0.05)。积极情绪诱发后(0.49±0.03),被试对条件化恐惧线索的再认正确率低于中性组(0.61±0.04),差异有统计学意义(P<0.05)。在消极情绪状态下,被试对恐惧线索的再认反应时高于积极主组和中性组[中性组、积极组与消极组在Day 2的再认反应时分别为(914.17±43.66)ms,(953.72±37.76)ms,(1483.49±157.64)ms,P<0.01]。结论积极情绪状态不但显著降低了对恐惧线索的皮肤电反应,还降低了对恐惧线索的再认水平;而消极情绪状态只增加了再认时的记忆提取时间,对恐惧相关线索的生理唤醒反应与再认率无明显作用。

Objective To explore the effects of emotion state on conditioned fear response and memory for conditioned fear cues.Methods Forty-eight undergraduate students were recruited as subjects.On Day 1,forty-eight participants underwent a partial reinforcement fear conditioning paradigm,using fruit or animal visual pictures as conditioned stimulus(CS)and loud white noise as the unconditioned stimulus(US).On Day 2,all subjects were divided into the neutral(n=16),negative(n=16)and positive(n=16)emotion groups according to the principle of gender matching.The emotion state of each group was manipulated by watching a 5 minutes'emotional film clip respectively.Then the fear-conditioning session was conducted again.On Day 3,recognition memory tests were conducted for the conditioned neutral items which presented randomly together with some new picture items.Results In the positive group,the skin conductance response(SCR)to conditioned fear cues after emotion induction((0.091±0.026)μs)was significantly lower than that before emotion induction((0.148±0.027)μs),and the difference was statistically significant(P<0.05).The recognition rate of positive group(0.49±0.03)for CS+presented on Day 2 was significantly lower than neutral group(0.61±0.04)(P<0.05).Under the negative emotional state,the recognition time of the subjects to the fear cues was higher than that of the positive group and the neutral group(the recognition time of Day 2 in neutral group,positive group and negative group were(914.17±43.66)ms,(953.72±37.76)ms,(1483.49±157.64)ms,respectively,P<0.01).Conclusion Positive emotion can not only inhibit the conditioned fear responses but also decrease the recognition rate for the conditioned neutral cues.Inducted negative emotion only increase the time recognition for the conditioned neutral cues,but it has no effect on the SCR and recognition rate.