Bannerman Rachel L, Milders Maarten, de Gelder Beatrice, Sahraie Arash
Vision Research Laboratories, School of Psychology, University of Aberdeen, Aberdeen AB24 2UB, UK. vision.abdn.ac.uk
Proc Biol Sci. 2009 May 7;276(1662):1635-41. doi: 10.1098/rspb.2008.1744. Epub 2009 Jan 20.
Most studies investigating speeded orientation towards threat have used manual responses. By measuring orienting behaviour using eye movements a more direct and ecologically valid measure of attention can be made. Here, we used a forced-choice saccadic and manual localization task to investigate the speed of discrimination for fearful and neutral body and face images. Fearful/neutral body or face pairs were bilaterally presented for either 20 or 500 ms. Results showed faster saccadic orienting to fearful body and face emotions compared with neutral only at the shortest presentation time (20 ms). For manual responses, faster discrimination of fearful bodies and faces was observed only at the longest duration (500 ms). More errors were made when localizing neutral targets, suggesting that fearful bodies and faces may have captured attention automatically. Results were not attributable to low-level image properties as no threat bias, in terms of reaction time or accuracy, was observed for inverted presentation. Taken together, the results suggest faster localization of threat conveyed both by the face and the body within the oculomotor system. In addition, enhanced detection of fearful body postures suggests that we can readily recognize threat-related information conveyed by body postures in the absence of any face cues.
大多数研究威胁快速定向的实验采用的是手动反应。通过测量眼动的定向行为,可以对注意力进行更直接且生态有效的测量。在此,我们使用了一个强制选择的扫视和手动定位任务,来研究对恐惧和中性的身体及面部图像的辨别速度。恐惧/中性的身体或面部图像对以双边形式呈现20毫秒或500毫秒。结果显示,仅在最短呈现时间(20毫秒)时,与中性刺激相比,对恐惧的身体和面部情绪的扫视定向更快。对于手动反应,仅在最长持续时间(500毫秒)时,才观察到对恐惧的身体和面部的辨别更快。在定位中性目标时会出现更多错误,这表明恐惧的身体和面部可能会自动吸引注意力。结果并非归因于低层次的图像属性,因为对于倒置呈现,在反应时间或准确性方面未观察到威胁偏向。综合来看,结果表明在动眼系统中,面部和身体所传达的威胁能被更快地定位。此外,对恐惧身体姿势的增强检测表明,在没有任何面部线索的情况下,我们能够轻易识别由身体姿势传达的与威胁相关的信息。