Bindemann Markus
Department of Psychology, University of Essex, CO4 3SQ, UK.
Vision Res. 2010 Nov 23;50(23):2577-87. doi: 10.1016/j.visres.2010.08.016. Epub 2010 Aug 21.
In laboratory studies of visual perception, images of natural scenes are routinely presented on a computer screen. Under these conditions, observers look at the center of scenes first, which might reflect an advantageous viewing position for extracting visual information. This study examined an alternative possibility, namely that initial eye movements are drawn towards the center of the screen. Observers searched visual scenes in a person detection task, while the scenes were aligned with the screen center or offset horizontally (Experiment 1). Two central viewing effects were observed, reflecting early visual biases to the scene and the screen center. The scene effect was modified by person content but is not specific to person detection tasks, while the screen bias cannot be explained by the low-level salience of a computer display (Experiment 2). These findings support the notion of a central viewing tendency in scene analysis, but also demonstrate a bias to the screen center that forms a potential artifact in visual perception experiments.
在视觉感知的实验室研究中，自然场景的图像通常会呈现在电脑屏幕上。在这些条件下，观察者首先会看向场景的中心，这可能反映出一个提取视觉信息的有利观察位置。本研究探讨了另一种可能性，即最初的眼动是被吸引到屏幕中心。观察者在一个人物检测任务中搜索视觉场景，同时场景与屏幕中心对齐或水平偏移（实验1）。观察到两种中央观察效应，反映了对场景和屏幕中心的早期视觉偏向。场景效应会因人物内容而改变，但并非人物检测任务所特有，而屏幕偏向不能用电脑显示器的低层次显著性来解释（实验2）。这些发现支持了场景分析中存在中央观察倾向的观点，但也证明了对屏幕中心的偏向，这在视觉感知实验中可能会形成一个潜在的假象。
