他人在场抑制条件性恐惧泛化

The Presence of Others Inhibited Fear Generalization

本研究采用经典的知觉辨别恐惧条件反射范式,将主观电击预期和皮肤电反应作为主要指标,考察他人在场对恐惧习得过程和恐惧泛化程度的影响。结果发现,恐惧习得过程未出现显著的组间差异。在恐惧泛化上,他人在场抑制了恐惧泛化水平,表现为皮肤电泛化水平更低、泛化梯度更广。研究初步证明,他人在场可能会分散个体的注意资源,降低个体的知觉辨别能力,进而抑制恐惧泛化。因此,他人在场在临床上对情绪障碍,特别是恐惧和焦虑相关障碍群体的干预作用值得重视。

In this study,we examined whether the presence of others leads to differentiated fear learning or fear generalization compared to the situation that individuals are alone.Eighty college students participated in this study.Three participants were excluded from analysis due to unsuccessful physiological recording.Five participants who could not learn the rules of shock were also excluded.Finally,we analyzed 72 participants'(Female:47,Male:25)behavioral and physiological data.The experiment had been conducted in two stages:acquisition and generalization.Ten increased-size rings served as conditioned stimuli(CS)and generalized stimuli(GS)respectively.The smallest and the largest rings were set as the conditioned threat stimuli(CS+)and conditioned safety stimuli(CS−),separately.The eight midsized rings were used as generalization stimuli(i.e.,Class1,Class2,Class3,Class4),with Class1 being the most similar to CS+in perception.The unconditioned stimulus(US)was a 500 ms electric shock,which was set at the level of"uncomfortable yet not painful".CS+was probably paired with the US(reinforcement rate:66.67%),whereas CS-was never paired with US.During the experiment,the online shock expectancy ratings of US and skin conductance responses were recorded.Our results showed that there was no difference between the groups in the fear acquisition phase.CS+has always resulted in higher shock expectancy and SCR amplitude than CS−.There was a tendency in the generalization test that the group with the presence of others had a higher shock expectancy,though it was not significant.In the index of SCR,the main effect of stimulus type depicted a downward gradient.The configuration of these downward gradients differed across groups,as evidenced by a significant"stimulus type×group"interaction.With respect to Class1,the presence of others group displayed a lower SCR amplitude than the alone group.In the alone group,Class1 induced a greater SCR than Class3 and Class 4,and Class 2 induced greater SCR than Class4,indexed by a steeper gradient than the presence of the other group.These results indicated that the presence of others inhibited the generalization of fear.According to the theory of negativity bias,threat stimuli would consume more attention resource,leading to a steady attentional bias.During the fear acquisition phase,participants'attentional resources were more easily captured by the novel fear stimuli,and thus ignored the presence of others.While in the subsequent generalization test,subjects had learned the rules of CS-US contingencies and therefore,the presence of others distracted subjects'attention.Our results suggested that the presence of others inhibited fear generalization at the physiological level,rather than at the subjective level.Furthermore,given that the watcher and the subject both came from the same university,our results indicated that the presence of others may have social buffering effect on fear generalization.Our findings may have potential implications for the etiology and treatment of fear-related anxiety disorders in clinical practice.