Background and objectives

Perceptual adaptations that facilitate rapid responses to threats can also lead to false alarms, or the failure to discriminate safe stimuli from signals of threat. We examined the impact of varying degrees of threat on false alarms in the perceptual discrimination of faces along the dimension of emotion (Experiment 1) or identity (Experiment 2).

Methods

Participants first trained to discriminate between a target and nontarget face. Next, we tested their ability to identify the target in randomized presentations of the target, the nontarget, and nine novel stimuli morphed in 10% increments of similarity from the target to the nontarget. The task was completed under one of three randomized conditions: 1) Ongoing-Threat paired the target with an aversive outcome in both phases; 2) Prior-Threat paired the target with an aversive outcome in the training phase only; and 3) No-Threat paired the target with a neutral outcome in the training phase only.

Results

In Experiment 1 (N = 90), Ongoing-Threat lowered the false alarm threshold for facial discrimination based on anger intensity compared to Prior-Threat and No-Threat. In Experiment 2 (N = 90), Ongoing-Threat and Prior-Threat each lowered the false alarm threshold for identity-based discrimination compared to No-Threat.

Limitations

The experiment did not measure generalization of threat responses.

Conclusion

Associating a facial expression or identity with threat leads to faster but less accurate discrimination of faces with similar features, particularly under conditions of ongoing threat. These experiments provide an avenue for examining the parameters that impact false alarms, which play a key role in anxiety disorders.

中文翻译：

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先前和持续威胁对面部识别误报阈值的影响

背景和目标

促进对威胁的快速响应的感知适应也可能导致误报，或无法将安全刺激与威胁信号区分开来。我们研究了不同程度的威胁对沿情感维度（实验 1）或身份维度（实验 2）的人脸感知辨别中误报的影响。

方法

参与者首先接受训练以区分目标面部和非目标面部。接下来，我们测试了他们在随机呈现的目标、非目标和九种新刺激中识别目标的能力，这些刺激从目标到非目标以 10% 的相似度递增。该任务是在三个随机条件之一下完成的：1) 持续威胁在两个阶段将目标与厌恶结果配对；2）Prior-Threat 仅在训练阶段将目标与厌恶结果配对；和 3) No-Threat 仅在训练阶段将目标与中性结果配对。

结果

在实验 1 (N = 90) 中，与先前威胁和无威胁相比，持续威胁降低了基于愤怒强度的面部识别误报阈值。在实验 2 (N = 90) 中，与无威胁相比，正在进行的威胁和先前的威胁都降低了基于身份的歧视的误报阈值。

限制

该实验没有测量威胁反应的概括。

结论

将面部表情或身份与威胁相关联会导致对具有相似特征的面部进行更快但不太准确的识别，尤其是在持续威胁的情况下。这些实验为检查影响误报的参数提供了途径，误报在焦虑症中起着关键作用。