Center for the Study of Emotion and Attention, University of Florida, USA.
Emotion. 2012 Oct;12(5):1050-60. doi: 10.1037/a0027069. Epub 2012 Mar 5.
Threatening faces involuntarily grab attention in socially anxious individuals. It is unclear, however, whether attention capture is at the expense of concurrent visual processing. The current study examined the perceptual cost effects of viewing fear-relevant stimuli (threatening faces) relative to a concurrent change-detection task. Steady-state visual evoked potentials (ssVEPs) were used to separate the neural response to 2 fully overlapping types of stimuli flickering at different frequencies: Task-irrelevant facial expressions (angry, neutral, happy) were overlaid with a task-relevant Gabor patch stream, which required a response to rare phase reversals. Groups of 17 high and 17 low socially anxious observers were recruited through online prescreening of 849 students. A prominent competition effect of threatening faces was observed solely in elevated social anxiety: When an angry face, relative to a neutral or happy face, served as a distractor, heightened ssVEP amplitudes were seen at the tagging frequency of that facial expression. Simultaneously, the ssVEP evoked by the task-relevant Gabor grating was reliably diminished compared with conditions with neutral or happy distractor faces. Thus, threatening faces capture and hold low-level perceptual resources in viewers symptomatic for social anxiety at the cost of a concurrent primary task. It is important to note that this competition in lower tier visual cortex was maintained throughout the viewing period and was unaccompanied by competition effects on behavioral performance.
威胁面孔会无意识地吸引社交焦虑个体的注意力。然而,目前尚不清楚注意力捕捉是否会影响到同时进行的视觉处理。本研究考察了观看与恐惧相关的刺激(威胁面孔)相对于同时进行的变化检测任务的感知成本效应。稳态视觉诱发电位(ssVEP)用于分离两种完全重叠的刺激的神经反应,这两种刺激以不同的频率闪烁:与任务无关的面部表情(愤怒、中性、快乐)与任务相关的伽伯补丁流重叠,需要对罕见的相位反转做出反应。通过对 849 名学生进行在线预筛选,招募了 17 名高社交焦虑和 17 名低社交焦虑的观察者。仅在社交焦虑程度升高的情况下观察到威胁面孔的明显竞争效应:当相对于中性或快乐面孔的愤怒面孔作为干扰物时,与该面部表情的标记频率相对应的 ssVEP 振幅会升高。同时,与中性或快乐干扰面孔的条件相比,与任务相关的伽伯光栅诱发的 ssVEP 确实减小了。因此,在社交焦虑症患者中,威胁面孔会以牺牲同时进行的主要任务为代价,捕捉并保持低层次的感知资源。需要注意的是,这种在较低层次视觉皮层中的竞争在整个观看期间都得到了维持,并且没有对行为表现产生竞争效应。