Galvin S J, O'Shea R P, Squire A M, Hailstone D S
Department of Psychology, University of Otago, Dunedin, New Zealand.
Vision Res. 1999 Aug;39(16):2649-57. doi: 10.1016/s0042-6989(98)00306-x.
In a previous study we found that blurred edges presented in peripheral vision look sharper than when they are looked at directly, a phenomenon we have called peripheral sharpness overconstancy (Galvin et al. (1997). Vision Research, 37, 2035-2039). In the current study we show that when visibility of the stimulus edges is compromised by very brief presentations, we can demonstrate sharpness overconstancy for static, foveal viewing. We also test whether the degree of sharpening is a function of the current visual context, but find no difference between the peripheral sharpness overconstancy (at 24 degrees eccentricity) of edges measured in a blurred context and that measured in a sharp context. We conclude that if the visual system does carry a template for sharp edges which contributes to edge appearance when visibility is poor, then that template is resistant to changes in context.
在之前的一项研究中,我们发现周边视觉中呈现的模糊边缘比直接注视时看起来更清晰,我们将这一现象称为周边锐度超恒常性(Galvin等人,《视觉研究》,1997年,第37卷,第2035 - 2039页)。在当前研究中,我们表明,当刺激边缘的可见性因非常短暂的呈现而受损时,我们可以证明在中央凹静态观察时存在锐度超恒常性。我们还测试了锐化程度是否是当前视觉环境的函数,但发现在模糊环境中测量的边缘(偏心度为24度)的周边锐度超恒常性与在清晰环境中测量的周边锐度超恒常性之间没有差异。我们得出结论,如果视觉系统确实携带了一个锐边模板,在可见性较差时有助于边缘外观的形成,那么该模板对环境变化具有抗性。