Laboratory of Cognitive Psychophysiology, Department of Natural Sciences, Federal Fluminense University, Rio das Ostras, Brazil.
Programa de pós-graduação em Medicina (Neurologia/Neurociências), Universidade Federal Fluminense, Niterói, Brasil.
Cogn Emot. 2024 Sep;38(6):954-962. doi: 10.1080/02699931.2024.2335535. Epub 2024 Mar 30.
Features of threatening cues and the associated context influence the perceived imminence of threat and the defensive responses evoked. To provide additional knowledge about how the directionality of a threat (i.e. directed-towards or away from the viewer) might impact defensive responses in humans, participants were shown pictures of a man carrying a gun (threat) or nonlethal object (neutral) directed-away from or towards the participant. Cardiac and electrodermal responses were collected. Compared to neutral images, threatening images depicting a gun directed-towards the participant induced sustained bradycardia and an increased electrodermal response, interpreted as immobility under attack. This defensive immobility reaction is evoked by high perceived threat and inescapable situations and indicates intense action preparation. Pictures of guns directed-away from the participant induced shorter bradycardia and no significant modulation of the electrodermal response compared to neutral pictures, which might be consistent with the perception of a less threatening situation. The results show that the directionality of threat stimuli is a key factor that prompts different patterns of defensive responses.
威胁线索的特征及其相关背景会影响人们对威胁的感知紧迫性和引发的防御反应。为了提供更多关于威胁的方向性（即指向观看者或远离观看者）如何影响人类防御反应的知识，参与者被展示了一个男人持枪（威胁）或非致命物体（中性）的图片，这些图片分别指向或远离参与者。收集了心脏和皮肤电反应。与中性图像相比，描绘枪指向参与者的威胁图像会引起持续的心动过缓和皮肤电反应增加，这被解释为在攻击下的不动反应。这种防御性的不动反应是由高度感知的威胁和无法逃脱的情况引起的，表明强烈的行动准备。与中性图片相比，指向参与者的枪的图片引起的心动过缓更短，皮肤电反应没有显著调节，这可能与感知到的威胁程度较低一致。研究结果表明，威胁刺激的方向性是促使不同防御反应模式的关键因素。
