von Wartburg Roman, Wurtz Pascal, Pflugshaupt Tobias, Nyffeler Thomas, Lüthi Mathias, Müri René M
Perception and Eye Movement Laboratory, Department of Neurology and Department of Clinical Research, University of Bern, Inselspital, CH 3010 Bern, Switzerland.
Perception. 2007;36(3):355-65. doi: 10.1068/p5552.
We investigated the effect of image size on saccade amplitudes. First, in a meta-analysis, relevant results from previous scene perception studies are summarised, suggesting the possibility of a linear relationship between mean saccade amplitude and image size. Forty-eight observers viewed 96 colour scene images scaled to four different sizes, while their eye movements were recorded. Mean and median saccade amplitudes were found to be directly proportional to image size, while the mode of the distribution lay in the range of very short saccades. However, saccade amplitudes expressed as percentages of image size were not constant over the different image sizes; on smaller stimulus images, the relative saccades were found to be larger, and vice versa. In sum, and as far as mean and median saccade amplitudes are concerned, the size of stimulus images is the dominant factor. Other factors, such as image properties, viewing task, or measurement equipment, are only of subordinate importance. Thus, the role of stimulus size has to be reconsidered, in theoretical as well as methodological terms.
我们研究了图像大小对扫视幅度的影响。首先，在一项荟萃分析中，总结了先前场景感知研究的相关结果，这表明平均扫视幅度与图像大小之间可能存在线性关系。48名观察者观看了96张按四种不同尺寸缩放的彩色场景图像，同时记录他们的眼球运动。结果发现，平均和中位数扫视幅度与图像大小成正比，而分布模式处于非常短的扫视范围内。然而，以图像大小百分比表示的扫视幅度在不同图像大小上并非恒定不变；在较小的刺激图像上，相对扫视幅度较大，反之亦然。总之，就平均和中位数扫视幅度而言，刺激图像的大小是主导因素。其他因素，如图像属性、观看任务或测量设备，仅具有次要重要性。因此，在理论和方法层面上，都必须重新考虑刺激大小的作用。
